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Bryan’s Chemistry <strong>Notebook</strong>


Honors Chemistry<br />

Class Policies and Grading<br />

The students will receive a Unit Outline at the beginning of each Unit. It will<br />

have information about the assignments that they will do, what it’s grade<br />

classification will be, what action they will need to do to complete the<br />

assignment and when it is due.<br />

The students will receive a Weekly Memo of the activities they will be<br />

responsible for that week. It will serve to inform the students of the learning<br />

goal for the week. It will also give the students any special information<br />

about that week.<br />

The students will also receive daily lectures and assignments that are<br />

designed to teach and re-enforce information related to the learning goal.<br />

This will be time in which new material will be taught and reviewed and will<br />

give the students the opportunity to ask questions regarding the concepts<br />

being taught.<br />

The students will work with a Lab partner and also be in a Lab group, but it<br />

will be up to the individual student to do his or her part of all assignments<br />

and the individual student will ultimately be responsible for all information<br />

presented in the class.<br />

The students will be required to follow all District and School Policies and to<br />

follow all Lab Safety Procedures, which they will be given and will sign,<br />

while performing labs. Students should come to class on time and with the<br />

supplies needed for that class.<br />

The following grading policy will be used.<br />

Percent of Final Grade<br />

<strong>Notebook</strong> 40%<br />

Test/Projects 30%<br />

Labs/Quizzes 20%<br />

Work 10%<br />

The students will be given a teacher generated Mid Term and a District<br />

Final.<br />

0


Unit 1<br />

Measurement Lab<br />

Separation of Mixtures Lab with Lab Write Up<br />

Unit 2<br />

Flame Test Lab<br />

Nuclear Decay Lab<br />

Element Marketing Project<br />

Unit 3<br />

Golden Penny Lab with Lab Write Up<br />

Molecular Geometry<br />

Research Presentation on a Chemical<br />

Mid Term<br />

Unit 4<br />

Double Displacement Lab<br />

Stoichiometry Lab with Lab Write Up<br />

Mole Educational Demonstration Project<br />

Unit 5<br />

Gas Laws Lab with Lab Write Up<br />

States of Matter Lab<br />

Teach a Gas Law Project<br />

Unit 6<br />

Dilutions Lab<br />

Titration Lab<br />

District Final<br />

1


Unit 1 (22 days)<br />

Chapter 1 Introduction to Chemistry<br />

Honors Chemistry<br />

2016/2017 Syllabus<br />

3 days<br />

1.1 The Scope of Chemistry 1.3 Thinking Like a Scientist<br />

1.2 Chemistry and You 1.4 Problem Solving in Chemistry<br />

Chapter 2 Matter and Change<br />

2.1 Properties of Matter 2.3 Elements and Compounds<br />

2.2 Mixtures 2.4 Chemical Reactions<br />

Chapter 3 Scientific Measurement<br />

9 days<br />

10 days<br />

3.1 Using and Expressing Measurements 3.3 Solving Conversion Problems<br />

3.2 Units of Measurement<br />

Unit 2 (15 days)<br />

Chapter 4 Atomic Structure<br />

5 days<br />

4.1 Defining the Atom 4.3 Distinguishing Among Atoms<br />

4.2 Structure of the Nuclear Atom<br />

Chapter 5 Electrons in Atoms<br />

5 days<br />

5.1 Revising the Atomic Model 5.2 Electron Arrangement in Atoms<br />

5.3 Atomic Emission Spectrum and the Quantum Mechanical Model<br />

Chapter 6 The Periodic Table<br />

6.1 Organizing the Elements 6.3 Periodic Trends<br />

6.2 Classifying Elements<br />

Unit 3 (22 days)<br />

Chapter 25 Nuclear Chemistry<br />

25.1 Nuclear Radiation 25.3 Fission and Fusion<br />

25.2 Nuclear Transformations 25.4 Radiation in Your Life<br />

Chapter 7 Ionic and Metallic Bonding<br />

7.1 Ions 7.3 Bonding in Metals<br />

7.2 Ionic Bonds and Ionic Compounds<br />

Chapter 8 Covalent Bonding<br />

5 days<br />

6 days<br />

8 days<br />

8 days<br />

8.1 Molecular Compounds 8.3 Bonding Theories<br />

8.2 The Nature of Covalent Bonding 8.4 Polar Bonds and Molecules<br />

Unit 4 (14 days)<br />

Chapter 9 Chemical Names and Formulas<br />

6 days<br />

9.1 Naming Ions 9.3 Naming & Writing Formulas Molecular Compounds<br />

9.2 Naming and Writing Formulas for Ionic Compounds 9.4 Names for Acids and Bases<br />

Chapter 22 Hydrocarbons Compounds<br />

22.1 Hydrocarbons 22.4 Hydrocarbon Rings<br />

Chapter 23 Functional Groups<br />

4 days<br />

4 days<br />

23.1 Introduction to Functional Groups 23.4 Alcohols, Ethers, and Amines<br />

2


Unit 5 (28 days)<br />

Chapter 10 Chemical Quantities 8 days<br />

10.1 The Mole: A Measurement of Matter 10.3 % Composition & Chem. Formulas<br />

10.2 Mole-Mass and Mole-Volume Relationships<br />

Chapter 11 Chemical Reactions 8 days<br />

11.1 Describing Chemical Reactions 11.3 Reactions in Aqueous Solutions<br />

11.2 Types of Chemical Reactions<br />

Chapter 12 Stoichiometry 12 days<br />

12.1 The Arithmetic of Equations 12.3 Limiting Reagent and % Yield<br />

12.2 Chemical Calculations<br />

Unit 6 (22 days)<br />

Chapter 13 States of Matter 6 days<br />

13.1 The Nature of Gases 13.3 The Nature of Solids<br />

13.2 The Nature of Liquids 13.4 Changes in State<br />

Chapter 14 The Behavior of Gases 10 days<br />

14.1 Properties of Gases 14.3 Ideal Gases<br />

14.2 The Gas Laws 14.4 Gases: Mixtures and Movement<br />

Chapter 15 Water and Aqueous Systems 6 days<br />

15.1 Water and its Properties 15.3 Heterogeneous Aqueous Systems<br />

15.2 Homogeneous Aqueous Systems<br />

Unit 7 (18 days)<br />

Chapter 16 Solutions 8 days<br />

16.1 Properties of Solutions 16.3 Colligative Properties of Solutions<br />

16.2 Concentrations of Solutions 16.4 Calc. Involving Colligative Property<br />

Chapter 17 Thermochemistry 5 days<br />

17.1 The Flow of Energy 17.3 Heat in Changes of State<br />

17.2 Measuring and Expressing Enthalpy Change 17.4 Calculating Heats in Reactions<br />

Chapter 18 Reaction Rates and Equilibrium 5 days<br />

18.1 Rates of Reactions 18.3 Reversible Reaction & Equilibrium<br />

18.2 The Progress of Chemical Reactions 18.5 Free Energy and Entropy<br />

Unit 8 (14 days)<br />

Chapter 19 Acid and Bases 10 days<br />

19.1 Acid-Base Theories 19.4 Neutralization Reactions<br />

19.2 Hydrogen Ions and Acidity 19.5 Salts in Solutions<br />

19.3 Strengths of Acids and Bases<br />

Chapter 20 Oxidation-Reduction Reactions 4 days<br />

20.1 The Meaning of Oxidation and Reduction 20.3 Describing Redox Equations<br />

20.2 Oxidation Numbers<br />

3


Lorenzo Walker Technical High School<br />

MUSTANG LABORATORIES<br />

Chemistry Safety<br />

Safety in the MUSTANG LABORATORIES - Chemistry Laboratory<br />

Working in the chemistry laboratory is an interesting and rewarding experience. During your labs, you will be actively<br />

involved from beginning to end—from setting some change in motion to drawing some conclusion. In the laboratory, you<br />

will be working with equipment and materials that can cause injury if they are not handled properly.<br />

However, the laboratory is a safe place to work if you are careful. Accidents do not just happen; they are caused—by<br />

carelessness, haste, and disregard of safety rules and practices. Safety rules to be followed in the laboratory are listed<br />

below. Before beginning any lab work, read these rules, learn them, and follow them carefully.<br />

General<br />

1. Be prepared to work when you arrive at the lab. Familiarize yourself with the lab procedures before beginning the lab.<br />

2. Perform only those lab activities assigned by your teacher. Never do anything in the laboratory that is not called for in<br />

the laboratory procedure or by your teacher. Never work alone in the lab. Do not engage in any horseplay.<br />

3. Work areas should be kept clean and tidy at all times. Only lab manuals and notebooks should be brought to the work<br />

area. Other books, purses, brief cases, etc. should be left at your desk or placed in a designated storage area.<br />

4. Clothing should be appropriate for working in the lab. Jackets, ties, and other loose garments should be removed. Open<br />

shoes should not be worn.<br />

5. Long hair should be tied back or covered, especially in the vicinity of open flame.<br />

6. Jewelry that might present a safety hazard, such as dangling necklaces, chains, medallions, or bracelets should not be<br />

worn in the lab.<br />

7. Follow all instructions, both written and oral, carefully.<br />

8. Safety goggles and lab aprons should be worn at all times.<br />

9. Set up apparatus as described in the lab manual or by your teacher. Never use makeshift arrangements.<br />

10. Always use the prescribed instrument (tongs, test tube holder, forceps, etc.) for handling apparatus or equipment.<br />

11. Keep all combustible materials away from open flames.<br />

12. Never touch any substance in the lab unless specifically instructed to do so by your teacher.<br />

13. Never put your face near the mouth of a container that is holding chemicals.<br />

14. Never smell any chemicals unless instructed to do so by your teacher. When testing for odors, use a wafting motion to<br />

direct the odors to your nose.<br />

15. Any activity involving poisonous vapors should be conducted in the fume hood.<br />

16. Dispose of waste materials as instructed by your teacher.<br />

17. Clean up all spills immediately.<br />

18. Clean and wipe dry all work surfaces at the end of class. Wash your hands thoroughly.<br />

19. Know the location of emergency equipment (first aid kit, fire extinguisher, fire shower, fire blanket, etc.) and how to use them.<br />

20. Report all accidents to the teacher immediately.<br />

Handling Chemicals<br />

21. Read and double check labels on reagent bottles before removing any reagent. Take only as much reagent as you<br />

need.<br />

22. Do not return unused reagent to stock bottles.<br />

23. When transferring chemical reagents from one container to another, hold the containers out away from your body.<br />

24. When mixing an acid and water, always add the acid to the water.<br />

25. Avoid touching chemicals with your hands. If chemicals do come in contact with your hands, wash them immediately.<br />

26. Notify your teacher if you have any medical problems that might relate to lab work, such as allergies or asthma.<br />

27. If you will be working with chemicals in the lab, avoid wearing contact lenses. Change to glasses, if possible, or notify<br />

the teacher.<br />

Handling Glassware<br />

28. Glass tubing, especially long pieces, should be carried in a vertical position to minimize the likelihood of breakage and<br />

to avoid stabbing anyone.<br />

29. Never handle broken glass with your bare hands. Use a brush and dustpan to clean up broken glass. Dispose of the<br />

glass as directed by your teacher.<br />

4


30. Always lubricate glassware (tubing, thistle tubes, thermometers, etc.) with water or glycerin before attempting to insert<br />

it into a rubber stopper.<br />

31. Never apply force when inserting or removing glassware from a stopper. Use a twisting motion. If a piece of glassware<br />

becomes "frozen" in a stopper, take it to your teacher.<br />

32. Do not place hot glassware directly on the lab table. Always use an insulating pad of some sort.<br />

33. Allow plenty of time for hot glass to cool before touching it. Hot glass can cause painful burns. (Hot glass looks cool.)<br />

Heating Substances<br />

34. Exercise extreme caution when using a gas burner. Keep your head and clothing away from the flame.<br />

35. Always turn the burner off when it is not in use.<br />

36. Do not bring any substance into contact with a flame unless instructed to do so.<br />

37. Never heat anything without being instructed to do so.<br />

38. Never look into a container that is being heated.<br />

39. When heating a substance in a test tube, make sure that the mouth of the tube is not pointed at yourself or anyone<br />

else.<br />

40. Never leave unattended anything that is being heated or is visibly reacting.<br />

First Aid in the MUSTANG LABORATORIES - Chemistry Laboratory<br />

Accidents do not often happen in well-equipped chemistry laboratories if students understand safe laboratory procedures<br />

and are careful in following them. When an occasional accident does occur, it is likely to be a minor one.<br />

The instructor will assist in treating injuries such as minor cuts and burns. However, for some types of injuries, you must<br />

take action immediately. The following information will be helpful to you if an accident occurs.<br />

1. Shock. People who are suffering from any severe injury (for example, a bad burn or major loss of blood) may be in a<br />

state of shock. A person in shock is usually pale and faint. The person may be sweating, with cold, moist skin and a weak,<br />

rapid pulse. Shock is a serious medical condition. Do not allow a person in shock to walk anywhere—even to the campus<br />

security office. While emergency help is being summoned, place the victim face up in a horizontal position, with the feet<br />

raised about 30 centimeters. Loosen any tightly fitting clothing and keep him or her warm.<br />

2. Chemicals in the Eyes. Getting any kind of a chemical into the eyes is undesirable, but certain chemicals are<br />

especially harmful. They can destroy eyesight in a matter of seconds. Because you will be wearing safety goggles at all<br />

times in the lab, the likelihood of this kind of accident is remote. However, if it does happen, flush your eyes with water<br />

immediately. Do NOT attempt to go to the campus office before flushing your eyes. It is important that flushing with water<br />

be continued for a prolonged time—about 15 minutes.<br />

3. Clothing or Hair on Fire. A person whose clothing or hair catches on fire will often run around hysterically in an<br />

unsuccessful effort to get away from the fire. This only provides the fire with more oxygen and makes it burn faster. For<br />

clothing fires, throw yourself to the ground and roll around to extinguish the flames. For hair fires, use a fire blanket to<br />

smother the flames. Notify campus security immediately.<br />

4. Bleeding from a Cut. Most cuts that occur in the chemistry laboratory are minor. For minor cuts, apply pressure to the<br />

wound with a sterile gauze. Notify campus security of all injuries in the lab. If the victim is bleeding badly, raise the<br />

bleeding part, if possible, and apply pressure to the wound with a piece of sterile gauze. While first aid is being given,<br />

someone else should notify the campus security officer.<br />

5. Chemicals in the Mouth. Many chemicals are poisonous to varying degrees. Any chemical taken into the mouth<br />

should be spat out and the mouth rinsed thoroughly with water. Note the name of the chemical and notify the campus<br />

office immediately. If the victim swallows a chemical, note the name of the chemical and notify campus security<br />

immediately.<br />

If necessary, the campus security officer or administrator will contact the Poison Control Center, a hospital emergency<br />

room, or a physician for instructions.<br />

6. Acid or Base Spilled on the Skin.<br />

Flush the skin with water for about 15 minutes. Take the victim to the campus office to report the injury.<br />

7. Breathing Smoke or Chemical Fumes.<br />

All experiments that give off smoke or noxious gases should be conducted in a well-ventilated fume hood. This will make<br />

an accident of this kind unlikely. If smoke or chemical fumes are present in the laboratory, all persons—even those who<br />

do not feel ill—should leave the laboratory immediately. Make certain that all doors to the laboratory are closed after the<br />

last person has left. Since smoke rises, stay low while evacuating a smoke-filled room. Notify campus security<br />

immediately.<br />

5


MUSTANG LABORATORIES<br />

COMMITMENT TO SAFETY IN THE LABORATORY<br />

As a student enrolled in Chemistry at Lorenzo Walker Technical High<br />

School, I agree to use good laboratory safety practices at all times. I<br />

also agree that I will:<br />

1. Conduct myself in a professional manner, respecting both my personal safety and the safety of<br />

others in the laboratory.<br />

2. Wear proper and approved safety glasses or goggles in the laboratory at all times.<br />

3. Wear sensible clothing and tie back long hair in the laboratory. Understand that open-toed shoes<br />

pose a hazard during laboratory classes and that contact lenses are an added safety risk.<br />

4. Keep my lab area free of clutter during an experiment.<br />

5. Never bring food or drink into the laboratory, nor apply makeup within the laboratory.<br />

6. Be aware of the location of safety equipment such as the fire extinguisher, eye wash station, fire<br />

blanket, first aid kit. Know the location of the nearest telephone and exits.<br />

7. Read the assigned lab prior to coming to the laboratory.<br />

8. Carefully read all labels on all chemical containers before using their contents, remove a small<br />

amount of reagent properly if needed, do not pour back the unused chemicals into the original<br />

container.<br />

9. Dispose of chemicals as directed by the instructor only. At no time will I pour anything down the<br />

sink without prior instruction.<br />

10. Never inhale fumes emitted during an experiment. Use the fume hood when instructed to do so.<br />

11. Report any accident immediately to the instructor, including chemical spills.<br />

12. Dispose of broken glass and sharps only in the designated containers.<br />

13. Clean my work area and all glassware before leaving the laboratory.<br />

14. Wash my hands before leaving the laboratory.<br />

NAME __________________________<br />

PERIOD ________________________<br />

PARENT NAME ____________________________<br />

PARENT NUMBER _________________________<br />

SIGNATURE ____________________________<br />

DATE ____________________________________<br />

6


7


Chapter 1<br />

Unit 1<br />

Introduction to Chemistry<br />

The students will learn why and how to solve problems using<br />

chemistry.<br />

Identify what is science, what clearly is not science, and what superficially<br />

resembles science (but fails to meet the criteria for science).<br />

Students will identify a phenomenon as science or not science.<br />

Inference<br />

Hypothesis<br />

Science<br />

Observation<br />

Identify which questions can be answered through science and which<br />

questions are outside the boundaries of scientific investigation, such as<br />

questions addressed by other ways of knowing, such as art, philosophy, and<br />

religion.<br />

Students will differentiate between problems and/or phenomenon that can and<br />

those that cannot be explained or answered by science.<br />

Students will differentiate between problems and/or phenomenon that can and<br />

those that cannot be explained or answered by science.<br />

Observation<br />

Inference<br />

Hypothesis<br />

Theory<br />

Controlled experiment<br />

Describe how scientific inferences are drawn from scientific observations<br />

and provide examples from the content being studied.<br />

Students will conduct and record observations.<br />

Students will make inferences.<br />

Students will identify a statement as being either an observation or inference.<br />

Students will pose scientific questions and make predictions based on<br />

inferences.<br />

Inference<br />

Observation<br />

Hypothesis<br />

Controlled experiment<br />

Identify sources of information and assess their reliability according to the<br />

strict standards of scientific investigation.<br />

Students will compare and assess the validity of known scientific information<br />

from a variety of sources:<br />

8


Print vs. print<br />

Online vs. online<br />

Print vs. online<br />

Students will conduct an experiment using the scientific method and compare<br />

with other groups.<br />

Controlled experiment<br />

Investigation<br />

Peer Review<br />

Accuracy<br />

Precision<br />

Percentage Error<br />

Chapter 2<br />

Matter and Change<br />

The students will learn what properties are used to describe<br />

matter and how matter can change its form.<br />

Differentiate between physical and chemical properties and physical and<br />

chemical changes of matter.<br />

Students will be able to identify physical and chemical properties of various<br />

substances.<br />

Students will be able to identify indicators of physical and chemical changes.<br />

Students will be able to calculate density.<br />

mass<br />

physical property<br />

volume<br />

chemical property<br />

vapor<br />

extensive property<br />

Chapter 3<br />

mixture<br />

intensive property<br />

solution<br />

element<br />

compound<br />

Scientific Measurements<br />

The students will be able to solve conversion problems using<br />

measurements.<br />

Determine appropriate and consistent standards of measurement for the<br />

data to be collected in a survey or experiment.<br />

Students will participate in activities to collect data using standardized<br />

measurement.<br />

Students will be able to manipulate/convert data collected and apply the data<br />

to scientific situations.<br />

Scientific notation<br />

International System of Units (SI)<br />

Significant figures<br />

Accepted value<br />

Experimental value<br />

Percent error<br />

Dimensional analysis<br />

9


10<br />

Learning Goal: Bechmark


To use the Stair-Step method, find the prefix the original measurement starts with. (ex. milligram)<br />

If there is no prefix, then you are starting with a base unit.<br />

Find the step which you wish to make the conversion to. (ex. decigram)<br />

Count the number of steps you moved, and determine in which direction you moved (left or right).<br />

The decimal in your original measurement moves the same number of places as steps you moved and in the<br />

same direction. (ex. milligram to decigram is 2 steps to the left, so 40 milligrams = .40 decigrams)<br />

If the number of steps you move is larger than the number you have, you will have to add zeros to hold the<br />

places. (ex. kilometers to meters is three steps to the right, so 10 kilometers would be equal to 10,000 m)<br />

That’s all there is to it! You need to be able to count to 6, and know your left from your right!<br />

1) Write the equivalent<br />

a) 5 dm =_______m b) 4 mL = ______L c) 8 g = _______mg<br />

d) 9 mg =_______g e) 2 mL = ______L f) 6 kg = _____g<br />

g) 4 cm =_______m h) 12 mg = ______ g i) 6.5 cm 3 = _______L<br />

j) 7.02 mL =_____cm 3 k) .03 hg = _______ dg l) 6035 mm _____cm<br />

m) .32 m = _______cm n) 38.2 g = _____kg<br />

11


2. One cereal bar has a mass of 37 g. What is the mass of 6 cereal bars? Is that more than or less<br />

than 1 kg? Explain your answer.<br />

3. Wanda needs to move 110 kg of rocks. She can carry l0 hg each trip. How many trips must she<br />

make? Explain your answer.<br />

4. Dr. O is playing in her garden again She needs 1 kg of potting soil for her plants. She has 750 g.<br />

How much more does she need? Explain your answer.<br />

5. Weather satellites orbit Earth at an altitude of 1,400,000 meters. What is this altitude in kilometers?<br />

6. Which unit would you use to measure the capacity? Write milliliter or liter.<br />

a) a bucket __________<br />

b) a thimble __________<br />

c) a water storage tank__________<br />

d) a carton of juice__________<br />

7. Circle the more reasonable measure:<br />

a) length of an ant 5mm or 5cm<br />

b) length of an automobile 5 m or 50 m<br />

c) distance from NY to LA 450 km or 4,500 km<br />

d) height of a dining table 75 mm or 75 cm<br />

8. Will a tablecloth that is 155 cm long cover a table that is 1.6 m long? Explain your answer.<br />

9. A dollar bill is 15.6 cm long. If 200 dollar bills were laid end to end, how many meters long would<br />

the line be?<br />

10. The ceiling in Jan’s living room is 2.5 m high. She has a hanging lamp that hangs down 41 cm.<br />

Her husband is exactly 2 m tall. Will he hit his head on the hanging lamp? Why or why not?<br />

12


Using SI Units<br />

Match the terms in Column II with the descriptions in Column I. Write the letters of the correct term in<br />

the blank on the left.<br />

Column I Column II<br />

_____ 1. distance between two points<br />

a. time<br />

_____ 2. SI unit of length<br />

_____ 3. tool used to measure length<br />

_____ 4. units obtained by combining other units<br />

_____ 5. amount of space occupied by an object<br />

_____ 6. unit used to express volume<br />

_____ 7. SI unit of mass<br />

_____ 8. amount of matter in an object<br />

_____ 9. mass per unit of volume<br />

_____ 10. temperature scale of most laboratory thermometers<br />

_____ 11. instrument used to measure mass<br />

_____ 12. interval between two events<br />

_____ 13. SI unit of temperature<br />

_____ 14. SI unit of time<br />

_____ 15. instrument used to measure temperature<br />

b. volume<br />

c. mass<br />

d. density<br />

e. meter<br />

f. kilogram<br />

g. derived<br />

h. liter<br />

i. second<br />

j. Kelvin<br />

k. length<br />

1. balance<br />

m. meterstick<br />

n. thermometer<br />

o. Celsius<br />

Circle the two terms in each group that are related. Explain how the terms are related.<br />

16. Celsius degree, mass, Kelvin _____________________________________________________<br />

________________________________________________________________________________<br />

17. balance, second, mass __________________________________________________________<br />

________________________________________________________________________________<br />

18. kilogram, liter, cubic centimeter __________________________________________________<br />

________________________________________________________________________________<br />

19. time, second, distance __________________________________________________________<br />

________________________________________________________________________________<br />

20. decimeter, kilometer, Kelvin _____________________________________________________<br />

________________________________________________________________________________<br />

13


1. How many meters are in one kilometer? __________<br />

2. What part of a liter is one milliliter? __________<br />

3. How many grams are in two dekagrams? __________<br />

4. If one gram of water has a volume of one milliliter, what would the mass of one liter of water be in<br />

kilograms?__________<br />

5. What part of a meter is a decimeter? __________<br />

In the blank at the left, write the term that correctly completes each statement. Choose from the terms<br />

listed below.<br />

Metric SI standard ten<br />

prefixes ten tenth<br />

6. An exact quantity that people agree to use for comparison is a ______________ .<br />

7. The system of measurement used worldwide in science is _______________ .<br />

8. SI is based on units of _______________ .<br />

9. The system of measurement that was based on units of ten was the _______________ system.<br />

10. In SI, _______________ are used with the names of the base unit to indicate the multiple of ten<br />

that is being used with the base unit.<br />

11. The prefix deci- means _______________ .<br />

14


Standards of Measurement<br />

Fill in the missing information in the table below.<br />

S.I prefixes and their meanings<br />

Prefix<br />

Meaning<br />

0.001<br />

0.01<br />

deci- 0.1<br />

10<br />

hecto- 100<br />

1000<br />

Circle the larger unit in each pair of units.<br />

1. millimeter, kilometer 4. centimeter, millimeter<br />

2. decimeter, dekameter 5. hectogram, kilogram<br />

3. hectogram, decigram<br />

6. In SI, the base unit of length is the meter. Use this information to arrange the following units of<br />

measurement in the correct order from smallest to largest.<br />

Write the number 1 (smallest) through 7 - (largest) in the spaces provided.<br />

_____ a. kilometer<br />

_____ b. centimeter<br />

_____ c. meter<br />

_____ e. hectometer<br />

_____ f. millimeter<br />

_____ g. decimeter<br />

_____ d. dekameter<br />

Use your knowledge of the prefixes used in SI to answer the following questions in the spaces<br />

provided.<br />

7. One part of the Olympic games involves an activity called the decathlon. How many events do you<br />

think make up the decathlon?_____________________________________________________<br />

8. How many years make up a decade? _______________________________________________<br />

9. How many years make up a century? ______________________________________________<br />

10. What part of a second do you think a millisecond is? __________________________________<br />

15


The Learning Goal for this assignment is:<br />

Notes Section<br />

1. 7,485 6. 1.683<br />

2. 884.2 7. 3.622<br />

3. 0.00002887 8. 0.00001735<br />

4. 0.05893 9. 0.9736<br />

5. 0.006162 10. 0.08558<br />

11. 6.633 X 10−⁴ 16. 1.937 X 10⁴<br />

12. 4.445 X 10−⁴ 17. 3.457 X 10⁴<br />

13. 2.182 X 10−³ 18. 3.948 X 10−⁵<br />

14. 4.695 X 10² 19. 8.945 X 10⁵<br />

15. 7.274 X 10⁵ 20. 6.783 X 10²<br />

16


SCIENTIFIC NOTATION RULES<br />

How to Write Numbers in Scientific Notation<br />

Scientific notation is a standard way of writing very large and very small numbers so that they're<br />

easier to both compare and use in computations. To write in scientific notation, follow the form<br />

N X 10 ᴬ<br />

where N is a number between 1 and 10, but not 10 itself, and A is an integer (positive or negative<br />

number).<br />

RULE #1: Standard Scientific Notation is a number from 1 to 9 followed by a decimal and the<br />

remaining significant figures and an exponent of 10 to hold place value.<br />

Example:<br />

5.43 x 10 2 = 5.43 x 100 = 543<br />

8.65 x 10 – 3 = 8.65 x .001 = 0.00865<br />

****54.3 x 10 1 is not Standard Scientific Notation!!!<br />

RULE #2: When the decimal is moved to the Left the exponent gets Larger, but the value of the<br />

number stays the same. Each place the decimal moves Changes the exponent by one (1). If you<br />

move the decimal to the Right it makes the exponent smaller by one (1) for each place it is moved.<br />

Example:<br />

6000. x 10 0 = 600.0 x 10 1 = 60.00 x 10 2 = 6.000 x 10 3 = 6000<br />

(Note: 10 0 = 1)<br />

All the previous numbers are equal, but only 6.000 x 10 3 is in proper Scientific Notation.<br />

17


RULE #3: To add/subtract in scientific notation, the exponents must first be the same.<br />

Example:<br />

(3.0 x 10 2 ) + (6.4 x 10 3 ); since 6.4 x 10 3 is equal to 64. x 10 2 . Now add.<br />

(3.0 x 10 2 )<br />

+ (64. x 10 2 )<br />

67.0 x 10 2 = 6.70 x 10 3 = 6.7 x 10 3<br />

67.0 x 10 2 is mathematically correct, but a number in standard scientific notation can only<br />

have one number to the left of the decimal, so the decimal is moved to the left one place and<br />

one is added to the exponent.<br />

Following the rules for significant figures, the answer becomes 6.7 x 10 3 .<br />

RULE #4: To multiply, find the product of the numbers, then add the exponents.<br />

Example:<br />

(2.4 x 10 2 ) (5.5 x 10 –4 ) = ? [2.4 x 5.5 = 13.2]; [2 + -4 = -2], so<br />

(2.4 x 10 2 ) (5.5 x 10 –4 ) = 13.2 x 10 –2 = 1.3 x 10 – 1<br />

RULE #5: To divide, find the quotient of the number and subtract the exponents.<br />

Example:<br />

(3.3 x 10 – 6 ) / (9.1 x 10 – 8 ) = ? [3.3 / 9.1 = .36]; [-6 – (-8) = 2], so<br />

(3.3 x 10 – 6 ) / (9.1 x 10 – 8 ) = .36 x 10 2 = 3.6 x 10 1<br />

18


Convert each number from Scientific Notation to real numbers:<br />

1. 7.485 X 10³ 6. 1.683 X 10⁰<br />

2. 8.842 X 10² 7. 3.622 10⁰<br />

3. 2.887 X 10−⁵ 8. 1.735 X 10−⁵<br />

4. 5.893 X 10−² 9. 9.736 X 10−¹<br />

5. 6.162 X 10−³ 10. 8.558 X 10−²<br />

Convert each number from a real number to Scientific Notation:<br />

11. 0.0006633 16. 1,937,000<br />

12. 0.0004445 17. 34,570<br />

13. 0.002182 18. 0.00003948<br />

14. 469.5 19. 894,500<br />

15. 727,400 20. 678.3<br />

19


The Learning Goal for this assignment is:<br />

Notes Section:<br />

Question Sig Figs Question Add & Subtract Question Multiple & Divide<br />

1 4 1 55.36 1 20,000<br />

2 4 2 84.2 2 94<br />

3 3 3 115.4 3 300<br />

4 3 4 0.8 4 7<br />

5 4 5 245.53 5 62<br />

6 3 6 34.5 6 0.005<br />

7 3 7 74.0 7 4,000<br />

8 2 8 53.287 8 3,900,000<br />

9 2 9 54.876 9 2<br />

10 2 10 40.19 10 30,000,000<br />

11 3 11 7.7 11 1,200<br />

12 2 12 67.170 12 0.2<br />

13 3 13 81.0 13 0.87<br />

14 4 14 73.290 14 0.049<br />

15 4 15 29.789 15 2,000<br />

16 3 16 39.53 16 0.5<br />

17 4 17 70.58 17 1.9<br />

18 2 18 86.6 18 0.05<br />

19 2 19 64.990 19 230<br />

20 1 20 36.0 20 460,000<br />

20


Significant Figures Rules<br />

There are three rules on determining how many significant figures are in a<br />

number:<br />

1. Non-zero digits are always significant.<br />

2. Any zeros between two significant digits are significant.<br />

3. A final zero or trailing zeros in the DECIMAL PORTION ONLY are<br />

significant.<br />

Please remember that, in science, all numbers are based upon measurements (except for a very few<br />

that are defined). Since all measurements are uncertain, we must only use those numbers that are<br />

meaningful.<br />

Not all of the digits have meaning (significance) and, therefore, should not be written down. In<br />

science, only the numbers that have significance (derived from measurement) are written.<br />

Rule 1: Non-zero digits are always significant.<br />

If you measure something and the device you use (ruler, thermometer, triple-beam, balance, etc.)<br />

returns a number to you, then you have made a measurement decision and that ACT of measuring<br />

gives significance to that particular numeral (or digit) in the overall value you obtain.<br />

Hence a number like 46.78 would have four significant figures and 3.94 would have three.<br />

Rule 2: Any zeros between two significant digits are significant.<br />

Suppose you had a number like 409. By the first rule, the 4 and the 9 are significant. However, to<br />

make a measurement decision on the 4 (in the hundred's place) and the 9 (in the one's place), you<br />

HAD to have made a decision on the ten's place. The measurement scale for this number would have<br />

hundreds, tens, and ones marked.<br />

Like the following example:<br />

These are sometimes called "captured zeros."<br />

If a number has a decimal at the end (after the one’s place) then all digits (numbers) are significant<br />

and will be counted.<br />

In the following example the zeros are significant digits and highlighted in blue.<br />

960.<br />

70050.<br />

21


Rule 3: A final zero or trailing zeros in the decimal portion ONLY are<br />

significant.<br />

This rule causes the most confusion among students.<br />

In the following example the zeros are significant digits and highlighted in blue.<br />

0.07030<br />

0.00800<br />

Here are two more examples where the significant zeros are highlighted in blue.<br />

When Zeros are Not Significant Digits<br />

4.7 0 x 10−³<br />

6.5 0 0 x 10⁴<br />

Zero Type # 1 : Space holding zeros in numbers less than one.<br />

In the following example the zeros are NOT significant digits and highlighted in red.<br />

0.09060<br />

0.00400<br />

These zeros serve only as space holders. They are there to put the decimal point in its correct<br />

location.<br />

They DO NOT involve measurement decisions.<br />

Zero Type # 2 : Trailing zeros in a whole number.<br />

In the following example the zeros are NOT significant digits and highlighted in red.<br />

200<br />

25000<br />

For addition and subtraction, look at the decimal portion (i.e., to the right of the decimal point)<br />

of the numbers ONLY. Here is what to do:<br />

1) Count the number of significant figures in the decimal portion of each number in the problem. (The<br />

digits to the left of the decimal place are not used to determine the number of decimal places in the<br />

final answer.)<br />

2) Add or subtract in the normal fashion.<br />

3) Round the answer to the LEAST number of places in the decimal portion of any number in the<br />

problem<br />

The following rule applies for multiplication and division:<br />

The LEAST number of significant figures in any number of the problem determines the number of<br />

significant figures in the answer.<br />

This means you MUST know how to recognize significant figures in order to use this rule.<br />

22


How Many Significant Digits for Each Number?<br />

Learning Goal: Benchmark<br />

1) 2359 = ______<br />

2) 2.445 x 10−⁵= ______<br />

3) 2.93 x 10⁴= ______<br />

4) 1.30 x 10−⁷= ______<br />

5) 2604 = ______<br />

6) 9160 = ______<br />

7) 0.0800 = ______<br />

8) 0.84 = ______<br />

9) 0.0080 = ______<br />

10) 0.00040 = ______<br />

11) 0.0520 = ______<br />

12) 0.060 = ______<br />

13) 6.90 x 10−¹= ______<br />

14) 7.200 x 10⁵= ______<br />

15) 5.566 x 10−²= ______<br />

16) 3.88 x 10⁸= ______<br />

.0000000388<br />

17) 3004 = ______<br />

18) 0.021 = ______<br />

19) 240 = ______<br />

20) 500 = ______<br />

23


For addition and subtraction, look at the decimal portion (i.e., to the right of the decimal point) of the<br />

numbers ONLY. Here is what to do:<br />

1) Count the number of significant figures in the decimal portion of each number in the problem. (The<br />

digits to the left of the decimal place are not used to determine the number of decimal places in the<br />

final answer.)<br />

2) Add or subtract in the normal fashion.<br />

3) Round the answer to the LEAST number of places in the decimal portion of any number in the<br />

problem.<br />

Solve the Problems and Round Accordingly...<br />

Learning Goal: Benchmark<br />

1) 43.287 + 5.79 + 6.284 = _______<br />

2) 87.54 - 3.3 = _______<br />

3) 99.1498 + 6.5397 + 9.7 = _______<br />

4) 5.868 - 5.1 = _______<br />

5) 59.9233 + 86.21 + 99.396 = _______<br />

6) 7.7 + 26.756 = _______<br />

7) 66.8 + 2.3 + 4.8516 = _______<br />

8) 9.7419 + 43.545 = _______<br />

9) 4.8976 + 48.4644 + 1.514 = _______<br />

10) 4.335 + 35.85 = _______<br />

11) 9.448 - 1.7 = _______<br />

12) 75.826 - 8.6555 = _______<br />

13) 57.2 + 23.814 = _______<br />

14) 77.684 - 4.394 = _______ 73.29<br />

15) 26.4496 + 3.339 = _______ 29.79<br />

16) 9.6848 + 29.85 = _______ 39.53<br />

17) 63.11 + 2.5412 + 4.93 = _______ 70.6<br />

18) 11.2471 + 75.4 = _______ 86.6<br />

19) 73.745 - 8.755 = _______ 64.99<br />

20) 6.5238 + 1.7 + 27.79 = _______ 36<br />

24


The following rule applies for multiplication and division:<br />

The LEAST number of significant figures in any number of the problem determines the number of<br />

significant figures in the answer.<br />

This means you MUST know how to recognize significant figures in order to use this rule.<br />

Solve the Problems and Round Accordingly...<br />

1) 0.6 x 65.0 x 602 = __________<br />

2) 720 ÷ 7.7 = __________<br />

3) 929 x 0.3 = __________<br />

4) 300 ÷ 44.31 = __________<br />

5) 608 ÷ 9.8 = __________<br />

6) 0.06 x 0.079 = __________<br />

7) 0.008 x 72.91 x 7000 = __________<br />

8) 73.94 x 67 x 780 = __________<br />

9) 0.62 x 0.097 x 40 = __________<br />

10) 600 x 10 x 5030 = __________<br />

11) 5200 ÷ 4.46 = __________<br />

12) 0.0052 x 0.4 x 107 = __________<br />

13) 0.099 x 8.8 = __________<br />

14) 0.0095 x 5.2 = __________<br />

15) 8000 ÷ 4.62 = __________<br />

16) 0.6 x 0.8 = __________<br />

17) 2.84 x 0.66 = __________<br />

18) 0.5 x 0.09 = __________<br />

7 6.770480704<br />

62 62.04081633<br />

0.005 0.00474<br />

19) 8100 ÷ 34.84 = __________<br />

20) 8.24 x 6.9 x 8100 = __________<br />

4000 4082.96<br />

3900000 3864104.4<br />

2 2.4056<br />

30000000 30180000<br />

1200 1165.919283<br />

0.2 0.22256<br />

0.87 0.8712<br />

0.049 0.0494<br />

2000 1731.601732<br />

0.5 0.48<br />

1.9 1.8744<br />

0.05 0.045<br />

230 232.4913892<br />

460000 460533.6<br />

25


Dimensional Analysis<br />

This is a way to convert from one unit of a given substance to<br />

another unit using ratios or conversion units. What this video<br />

www.youtube.com/watch?v=aZ3J60GYo6U<br />

Let’ look at a couple of examples:<br />

1. Convert 2.6 qt to mL.<br />

First we need a ratio or conversion unit so that we can go from quarts to milliliters. 1.00 qt = 946 mL<br />

Next write down what you are starting with<br />

2.6 qt<br />

Then make you conversion tree<br />

2.6 qt<br />

Then fill in the units in your ratio so that you can cancel out the original unit and will be left with the<br />

unit you need for the answer. Cross out units, one at a time that are paired, and one on top one on<br />

the bottom.<br />

2.6 qt mL<br />

qt<br />

Now fill in the values from the ratio.<br />

2.6 qt 946 mL<br />

1.00 qt<br />

Now multiply all numbers on the top and multiply all numbers on the bottom and write them as a<br />

fraction.<br />

2.6 qt 946 mL = 2,459.6 mL<br />

1.00 qt 1.00<br />

Now divide the top number by the bottom number and write that number with the unit that was not<br />

crossed out.<br />

26


Learning Goal: Benchmark<br />

1qt=32 oz 1gal = 4qts 1.00 qt = 946 mL 1L = 1000mL<br />

2. Convert 8135.6 mL to quarts<br />

=<br />

3. Convert 115.2 oz to mL<br />

=<br />

4. Convert 2.3 g to Liters<br />

=<br />

5. Convert 8.42 L to oz<br />

=<br />

Go to http://science.widener.edu/svb/tutorial/ chose #7 “Converting Volume” and do 5 more in the<br />

space provided.<br />

1. Convert _________ to _________<br />

=<br />

2. Convert _________ to _________<br />

=<br />

3. Convert _________ to _________<br />

=<br />

4. Convert _________ to _________<br />

=<br />

5. Convert _________ to _________<br />

=<br />

27


Chapter 4<br />

Unit 2<br />

Atomic Structure<br />

The students will learn what makes up atoms and how are<br />

atoms of one element different from atoms of another element.<br />

Explore the scientific theory of atoms (also known as atomic theory) by<br />

describing changes in the atomic model over time and why those changes<br />

were necessitated by experimental evidence.<br />

<br />

<br />

<br />

Students will be able to draw/identify each atomic model.<br />

Students will be able to compare/contrast the different atomic models.<br />

Students will be able to describe how results of experimental evidence caused<br />

the atomic model to change.<br />

proton<br />

electron<br />

neutron<br />

nucleus<br />

electron cloud<br />

Explore the scientific theory of atoms (also known as atomic theory) by<br />

describing the structure of atoms in terms of protons, neutrons and<br />

electrons, and differentiate among these particles in terms of their mass,<br />

electrical charges and locations within the atom.<br />

<br />

Students will compare/contrast the characteristics of subatomic particles.<br />

atomic number<br />

mass number<br />

isotope<br />

atomic mass unit (amu)<br />

atomic mass


Chapter 5<br />

Electrons in Atoms<br />

The students will be able to describe the arrangement of<br />

electrons in atoms and predict what will happen when<br />

electrons in atoms absorb or release energy.<br />

Describe the quantization of energy at the atomic level.<br />

Students will participate in activities to view emission spectrums using a<br />

diffraction grating or a spectroscope.<br />

Students will be able to explain how the spectrum lines relate to electron motion.<br />

energy level<br />

atomic orbital<br />

quantum mechanical model<br />

Chapter 6<br />

The Periodic Table<br />

The student will learn what information the periodic table<br />

provides and how periodic trends can be explained.<br />

Relate properties of atoms and their position in the periodic table to the<br />

arrangement of their electrons.<br />

Students will be able to compare and contrast metals, nonmetals, and metalloids.<br />

Students will be able to describe the traits of various families on the periodic<br />

table.<br />

Students will be able to explain periodicity.<br />

Students will write/represent electron configuration of various elements.<br />

Students will be able to use a periodic table to calculate the number of p + , e - , and<br />

n 0 .<br />

Students will be able to calculate the average weight of mass.<br />

periodic law<br />

halogen<br />

metals<br />

noble gas<br />

nonmetals<br />

transition metal<br />

metalloid<br />

atomic radius<br />

alkali metal<br />

ionization energy<br />

alkaline earth metal<br />

electronegativity


The Learning Goal for this assignment is:<br />

Ch 5 The students will learn what makes up atoms and how are atoms of one element<br />

different from atoms of another element.<br />

Ch 6<br />

The student will learn what information the periodic table provides and how periodic<br />

trends can be explained.<br />

Notes Section<br />

http://www.learner.org/interactives/periodic/basics_interactive.html


Atoms Are Building Blocks<br />

Atoms are the basis of chemistry. They are the basis for everything in the Universe. You<br />

should start by remembering that matter is composed of atoms. Atoms and the study of<br />

atoms are a world unto themselves. We're going to cover basics like atomic structure<br />

and bonding between atoms.<br />

Smaller Than Atoms?<br />

Are there pieces of matter that are smaller than atoms?<br />

Sure there are. You'll soon be learning that atoms are<br />

composed of pieces like electrons, protons, and neutrons.<br />

But guess what? There are even smaller particles moving<br />

around in atoms. These super-small particles can be found<br />

inside the protons and neutrons. Scientists have many<br />

names for those pieces, but you may have heard of<br />

nucleons and quarks. Nuclear chemists and physicists<br />

work together at particle accelerators to discover the<br />

presence of these tiny, tiny, tiny pieces of matter.<br />

Even though super-tiny atomic particles exist, you only<br />

need to remember the three basic parts of an atom: electrons, protons, and neutrons.<br />

What are electrons, protons, and neutrons? A picture works best to show off the idea.<br />

You have a basic atom. There are three types of pieces in that atom: electrons, protons,<br />

and neutrons. That's all you have to remember. Three things! As you know, there are<br />

almost 120 known elements in the periodic table. Chemists and physicists haven't<br />

stopped there. They are trying to make new ones in labs every day. The thing that<br />

makes each of those elements different is the number of electrons, protons, and<br />

neutrons. The protons and neutrons are always in the center of the atom. Scientists call<br />

the center region of the atom the nucleus. The nucleus in<br />

a cell is a thing. The nucleus in an atom is a place where<br />

you find protons and neutrons. The electrons are always<br />

found whizzing around the center in areas called shells or<br />

orbitals.<br />

You can also see that each piece has either a "+", "-", or a<br />

"0." That symbol refers to the charge of the particle. Have<br />

you ever heard about getting a shock from a socket, static<br />

electricity, or lightning? Those are all different types of<br />

electric charges. Those charges are also found in tiny particles of matter. The electron<br />

always has a "-", or negative, charge. The proton always has a "+", or positive, charge. If<br />

the charge of an entire atom is "0", or neutral, there are equal numbers of positive and<br />

negative pieces. Neutral means there are equal numbers of electrons and protons. The<br />

third particle is the neutron. It has a neutral charge, also known as a charge of zero. All<br />

atoms have equal numbers of protons and electrons so that they are neutral. If there are<br />

more positive protons or negative electrons in an atom, you have a special atom called<br />

an ion.


Looking at Ions<br />

We haven’t talked about ions before, so let’s get down to basics. The<br />

atomic number of an element, also called a proton number, tells you the<br />

number of protons or positive particles in an atom. A normal atom has a<br />

neutral charge with equal numbers of positive and negative particles.<br />

That means an atom with a neutral charge is one where the number of<br />

electrons is equal to the atomic number. Ions are atoms with extra<br />

electrons or missing electrons. When you are missing an electron or<br />

two, you have a positive charge. When you have an extra electron<br />

or two, you have a negative charge.<br />

What do you do if you are a sodium (Na) atom? You have eleven<br />

electrons — one too many to have an entire shell filled. You need to<br />

find another element that will take that electron away from you. When you lose that<br />

electron, you will you’ll have full shells. Whenever an atom has full shells, we say it is<br />

"happy." Let's look at chlorine (Cl). Chlorine has seventeen electrons and only needs<br />

one more to fill its third shell and be "happy." Chlorine will take your extra sodium<br />

electron and leave you with 10 electrons inside of two filled shells. You are now a happy<br />

atom too. You are also an ion and missing one electron. That missing electron gives you<br />

a positive charge. You are still the element sodium, but you are now a sodium ion (Na + ).<br />

You have one less electron than your atomic number.<br />

Ion Characteristics<br />

So now you've become a sodium ion. You have ten electrons.<br />

That's the same number of electrons as neon (Ne). But you<br />

aren't neon. Since you're missing an electron, you aren't really<br />

a complete sodium atom either. As an ion you are now<br />

something completely new. Your whole goal as an atom was<br />

to become a "happy atom" with completely filled electron<br />

shells. Now you have those filled shells. You have a lower<br />

energy. You lost an electron and you are "happy." So what<br />

makes you interesting to other atoms? Now that you have<br />

given up the electron, you are quite electrically attractive.<br />

Other electrically charged atoms (ions) of the opposite charge<br />

(negative) are now looking at you and seeing a good partner to<br />

bond with. That's where the chlorine comes in. It's not only chlorine. Almost any ion with<br />

a negative charge will be interested in bonding with you.


Electrovalence<br />

Don't get worried about the big word. Electrovalence is just another word for something<br />

that has given up or taken electrons and become an ion. If you look at the periodic table,<br />

you might notice that elements on the left side usually become positively charged ions<br />

(cations) and elements on the right side get a negative charge (anions). That trend<br />

means that the left side has a positive valence and the right side has a negative<br />

valence. Valence is a measure of how much an atom wants to bond with other atoms. It<br />

is also a measure of how many electrons are excited about bonding with other atoms.<br />

There are two main types of bonding, covalent and electrovalent. You may have heard<br />

of the term "ionic bonds." Ionic bonds are electrovalent bonds. They are just groups of<br />

charged ions held together by electric forces. When in the presence of other ions, the<br />

electrovalent bonds are weaker because of outside electrical forces and attractions.<br />

Sodium and chlorine ions alone have a very strong bond, but as soon as you put those<br />

ions in a solution with H + (Hydrogen ion), OH - (Hydroxide), F - (Fluorine ion) or Mg ++<br />

(Magnesium ion), there are charged distractions that break the Na-Cl bond.<br />

Look at sodium chloride (NaCl) one more time. Salt is a very strong bond when it is<br />

sitting on your table. It would be nearly impossible to break those ionic/electrovalent<br />

bonds. However, if you put that salt into some water (H2O), the bonds break very<br />

quickly. It happens easily because of the electrical attraction of the water. Now you have<br />

sodium (Na + ) and chlorine (Cl - ) ions floating around the solution. You should remember<br />

that ionic bonds are normally strong, but they are very weak in water.


Neutron Madness<br />

We have already learned that ions are atoms that are<br />

either missing or have extra electrons. Let's say an atom<br />

is missing a neutron or has an extra neutron. That type of<br />

atom is called an isotope. An atom is still the same<br />

element if it is missing an electron. The same goes for<br />

isotopes. They are still the same element. They are just a<br />

little different from every other atom of the same element.<br />

For example, there are a lot of carbon (C) atoms in the<br />

Universe. The normal ones are carbon-12. Those atoms have 6 neutrons. There are a<br />

few straggler atoms that don't have 6. Those odd ones may have 7 or even 8 neutrons.<br />

As you learn more about chemistry, you will probably hear about carbon-14. Carbon-14<br />

actually has 8 neutrons (2 extra). C-14 is considered an isotope of the element carbon.<br />

Messing with the Mass<br />

If you have looked at a periodic table, you may have noticed that the atomic mass of<br />

an element is rarely an even number. That happens because of the isotopes. If you are<br />

an atom with an extra electron, it's no big deal. Electrons don't have much of a mass<br />

when compared to a neutron or proton.<br />

Atomic masses are calculated by figuring out the<br />

amounts of each type of atom and isotope there are in<br />

the Universe. For carbon, there are a lot of C-12, a<br />

couple of C-13, and a few C-14 atoms. When you<br />

average out all of the masses, you get a number that is a<br />

little bit higher than 12 (the weight of a C-12 atom). The<br />

average atomic mass for the element is actually 12.011.<br />

Since you never really know which carbon atom you are<br />

using in calculations, you should use the average mass<br />

of an atom.<br />

Bromine (Br), at atomic number 35, has a greater variety of isotopes. The atomic mass<br />

of bromine (Br) is 79.90. There are two main isotopes at 79 and 81, which average out<br />

to the 79.90amu value. The 79 has 44 neutrons and the 81 has 46 neutrons. While it<br />

won't change the average atomic mass, scientists have made bromine isotopes with<br />

masses from 68 to 97. It's all about the number of neutrons. As you move to higher<br />

atomic numbers in the periodic table, you will probably find even more isotopes for<br />

each element.


Summary


Electron Configuration<br />

Color the sublevel:<br />

s = Red<br />

d = Green<br />

p = Blue<br />

f = Orange<br />

s<br />

p<br />

d<br />

f<br />

1<br />

Write in sublevels<br />

1s 2<br />

1s 1<br />

2<br />

Write period, sublevel and super scripts.<br />

13 14 15 16 17<br />

7s 1 7s 2<br />

2s 1<br />

Ctrl Shift = gives you super scripts<br />

2s 2<br />

2p 1 2p 2 2p 3 2p 4 2p 5 2p 6<br />

3s 1 3s 2<br />

3 4 5 6 7 8 9 10 11 12 3p 1 3p 2 3p 3 3p 4 2p 5 2p 6<br />

4s 1 4s 2 3d 1 3d 2 3d 3 3d 4 3d 5 3d 6 3d 7 3d 8 3d 9 3d 10 4p 1 4p 2 4p 3 4p 4 4p 5 4p 6<br />

5s 1 5s 2 4d 1 4d 2 4d 3 4d 4 4d 5 4d 6 4d 7 4d 8 4d 9 4d 10 5p 1 5p 2 5p 3 5p 4 5p 5 5p 6<br />

6s 1 6s 2 5d 1 5d 2 5d 3 5d 4 5d 5 5d 6 5d 7 5d 8 5d 9 5d 10 6p 1 6p 2 6p 3 6p 4 6p 5 6p 6<br />

6d 1 6d 2 6d 3 6d 4 6d 5 6d 6 6d 7 6d 8 6d 9 6d 10<br />

18<br />

4f 1 4f 2 4f 3 4f 4 4f 5 4f 6 4f 7 4f 8 4f 9 4f 10 4f 11 4f 12 4f 13 4f 14<br />

5f 1 5f 2 5f 3 5f 4 5f 5 5f 6 5f 7 5f 8 5f 9 5f 10 5f 11 5f 12 5f 13 5f 14


The Learning Goal for this assignment is:<br />

Ch 6 The student will learn what information the periodic table provides and how periodic trends can be<br />

explained.<br />

Ch 5 The students will be able to describe the arrangement of electrons in atoms and predict what will happen<br />

when electrons in atoms absorb or release energy.<br />

www.youtube.com/watch?v=jtYzEzykFdg<br />

www.youtube.com/watch?<br />

annotation_id=annotation_2076&feature=iv&src_vid=jtYzEzykFdg&v=cOlac8ruD_0<br />

www.youtube.com/watch?<br />

annotation_id=annotation_570977&feature=iv&src_vid=cOlac8ruD_0&v=lR2vqHZWb5A<br />

Notes Section


Electron Configuration<br />

In order to write the electron configuration for an atom you must know the 3 rules of<br />

electron configurations.<br />

1. Aufbau<br />

Notation<br />

nO e<br />

where<br />

n is the energy level<br />

O is the orbital type (s, p, d, or f)<br />

e is the number of electrons in that orbital shell<br />

Principle<br />

electrons will first occupy orbitals of the lowest energy level<br />

2. Hund rule<br />

when electrons occupy orbitals of equal energy, one electron enters each orbital until<br />

all the orbitals contain one electron with the same spin.<br />

3. Pauli exclusion principle<br />

an orbital contains a maximum of 2 electrons and<br />

paired electrons will have opposite spin


In the space below, write the unabbreviated electron configurations of the following elements:<br />

1)<br />

1s<br />

sodium ________________________________________________<br />

,2s 2 ,2p 6 ,3s 1<br />

2) iron<br />

1s<br />

________________________________________________<br />

,2s 2 ,2p 6 ,3s 2 ,3p 6 ,4s 2 ,3d 6<br />

3) bromine ________________________________________________<br />

1s 2 ,2s 2 ,2p 6 ,3s 2 ,3p 6 ,4s 2 ,3d 10 ,4p 5<br />

4) barium ________________________________________________<br />

1s 2 ,2s 2 ,2p 6 ,3s 2 ,3p 6 ,4s 2 ,3d 10 ,4p 6 ,5s 2 ,4d 10 ,5p 6 ,6s 2<br />

5) neptunium 1s ________________________________________________<br />

,2s 2 ,2p 6 ,3s 2 ,3p 6 ,4s 2 ,3d 10 ,4p 6 ,5s 2 ,4d 10 ,5p 6 ,6s 2 ,4f 14 ,5d 10 ,6p 6 ,7s 2 ,5f 5<br />

In the space below, write the abbreviated electron configurations of the following elements:<br />

6) cobalt<br />

[Ar], 4s<br />

________________________________________________<br />

,3d 7<br />

7) silver<br />

[Kr],5s<br />

________________________________________________<br />

,4d 9<br />

8) tellurium<br />

[Kr],5s<br />

________________________________________________<br />

,4d 10 ,5p 4<br />

9) radium ________________________________________________<br />

[Rn],7s 2 [Rn],7s 2 ,5f 14 ,6d 1<br />

10) lawrencium ________________________________________________<br />

Determine what elements are denoted by the following electron configurations:<br />

11)<br />

Sulfur<br />

1s²s²2p⁶3s²3p⁴ ____________________<br />

12)<br />

Rubidium<br />

1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶5s¹ ____________________<br />

13)<br />

Antimony<br />

[Kr] 5s²4d¹⁰5p³ ____________________<br />

14)<br />

Osmium<br />

[Xe] 6s²4f¹⁴5d⁶ ____________________<br />

15) [Rn] 7s²5f¹¹ ____________________<br />

Einsteinium<br />

Identify the element or determine that it is not a valid electron configuration:<br />

16)<br />

4d should be 3d<br />

1s²2s²2p⁶3s²3p⁶4s²4d¹⁰4p⁵ ____________________<br />

17)<br />

3p comes after 3s<br />

1s²2s²2p⁶3s³3d⁵ ____________________<br />

18)<br />

[Ra] is not a noble gas<br />

[Ra] 7s²5f⁸ ____________________<br />

19)<br />

This is valid<br />

[Kr] 5s²4d¹⁰5p⁵ ____________________<br />

20)<br />

An element can't be its own electron configuration<br />

[Xe] ____________________<br />

1)sodium 1s 2 2s 2 2p 6 3s 1 2)iron 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 6<br />

3)bromine 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 5 4)barium 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 5s 2 4d 10 5p 6 6s 2<br />

5)neptunium 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 5s 2 4d 10 5p 6 6s 2 4f 14 5d 10 6p 6 7s 2 5f 5 6)cobalt [Ar] 4s 2 3d 7<br />

7)silver [Kr] 5s 2 4d 9 8)tellurium[Kr] 5s 2 4d 10 5p 4<br />

9)radium [Rn] 7s 2 10)lawrencium[Rn] 7s 2 5f 14 6d 1<br />

1s 2 2s 2 2p 6 3s 2 3p 4 sulfur 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 5s 1 rubidium<br />

[Kr] 5s 2 4d 10 5p 3 antimony [Xe] 6s 2 4f 14 5d 6 osmium<br />

[Rn] 7s 2 5f 11 einsteinium 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 4d 10 4p 5 not valid (take a look at “4d”)<br />

1s 2 2s 2 2p 6 3s 3 3d 5 not valid (3p comes after 3s) [Ra] 7s 2 5f 8 not valid (radium isn’t a noble gas)<br />

[Kr] 5s 2 4d 10 5p 5 valid iodine<br />

20)[Xe] not valid (an element can’t be its own electron configuration)


Calcium -CA


Create groups for these Scientist and explain your groupings<br />

(use the information you got from your research)<br />

Radiation Discovery<br />

Glenn Seaborg<br />

Atoine Henri Becquerel<br />

Marie and Pierre Curie<br />

Electrons<br />

J.J Thomson<br />

Louis de Barogilie<br />

Eugene Goldstein<br />

Robert Millikan<br />

Alpha Particles<br />

James Chadwick<br />

Ernst Rutherford<br />

Periodic Table<br />

J.W Dobereiner<br />

Lothar Meyer<br />

Dmitri Mendeleev<br />

Models<br />

Erwin Shodinger<br />

Hantaro Nagaoka<br />

Niels Bohr


Research the Scientist and summarize their contributions to the Atomic Theory<br />

Antoine Henri Becquerel<br />

Antoine found strange radioactivity in his experiments with different substances which helped him invent the x-ray. He the<br />

found out about the deflection of beta particles.<br />

Niels Bohr<br />

Niels contributed to to the understanding of the structures to atoms.He then found out about the development of quantum<br />

mechanics.<br />

Louis de Barogilie<br />

Louis studied quantum theory. He then predicted the wave natures of electrons.<br />

Glenn Seaborg<br />

Glenn isolated radioactive elements.He then formulated the actinide concept.<br />

Hantaro Nagaoka<br />

Hanatro contributed to the atom model. He also suggested that the electrons were outside of the atom.<br />

Democritus<br />

Democritus created the atomic theory. Which then helped future scientists.<br />

Marie and Pierre Curie<br />

Marie and Pierre studied on radioactivity. In which they discovered 2 elements named radium and polonium<br />

Eugene Goldstein<br />

Eugene concluded that cathode rays negativity charged travel towards the positively charged anode. He also thought abou<br />

electrons doing the same thing.<br />

Dmitri Mendeleev<br />

Dmitri contributed to the periodic table by putting elements into rows and colums. He did it by atomic mass and chemical/ph<br />

propertys.<br />

J.J. Thomson<br />

J.J. discovered electrons when doing a experiment with cathode ray. He also discovered that cathode is negativity<br />

charged.<br />

James Chadwick<br />

James discovered neutrons. He did it by combining beryllium atoms with alpha particles.<br />

Erwin Shrodinger<br />

Erwin contributed to the wave theory. Which involved matter and quantum mechanics.<br />

John Dalton<br />

John contributed to the atomic theory. He did it by concluding when atoms combine in a ratio it must be presumed to be a<br />

binary.<br />

Lothar Meyer<br />

Lothar was one of the first to create the periodic table. The periodic table he had contained 28 elements.<br />

Robert Millikan<br />

Robert did a oil drop experiment which helped us find the quantity of an electron. After he did this it then helped us<br />

understand the structure of the atom.<br />

J.W. Dobereiner<br />

J.W. observed the similarities of elements. It then help contribute with the periodic table.<br />

Ernest Rutherford<br />

Ernest discovered alpha and beta rays. He then set created the law of radioactive decay.


The Learning Goal for this Assignment is<br />

Ch 5 The students will be able to describe the arrangement of electrons in atoms and predict what will<br />

happen when electrons in atoms absorb or release energy.<br />

Ch 6 The student will learn what information the periodic table provides and how periodic trends can be<br />

explained.<br />

Alkali Metals<br />

Alkali Earth Metals<br />

Transitional Metals<br />

Inter Transitional Metals<br />

Metals<br />

Metalloids<br />

Non Metals<br />

Noble Gases


Using Wikipedia, define the 8 categories of elements on the<br />

left page.<br />

Color your periodic table similar to the one on<br />

pages 168—169 of your book.<br />

alkali metals<br />

alkaline metals<br />

other metals<br />

transitional metals<br />

lanthanoids<br />

metalloids<br />

non metals<br />

halogens<br />

noble gases<br />

unknown elements<br />

actinoids


Define Atomic Size:<br />

Atomic Size<br />

The size of the atom is determined by the size of the nucleus and the<br />

number of energy levels<br />

I<br />

n<br />

c<br />

r<br />

e<br />

a<br />

s<br />

e<br />

Explanation:<br />

When looking at groups the size of the atom increases when going from top to bottom<br />

because we added more energy levels. When looking at a period the size increases from the<br />

right to the left we increase mass which increases gravity which pulls in electrons.


Ionization Energy<br />

Define Ionization Energy:<br />

The energy required to remove an electron from an atom.<br />

Explanation: The closer the electrons are to the nucleus of the atom, the higher the atom's<br />

ionization energy. Due to this you can predict what ions an element will form.<br />

The cation produced has a 1+ charge.


Electronegativity<br />

Define Electronegativity:<br />

The ability of an atom of an element to attract electrons when the<br />

atom is in a compound.<br />

Explanation:<br />

Metals at the far left of the periodic table have low values. Nonmetals at the far right have<br />

high values. The noble gases are omitted because they do not form many compounds.


Ion Size<br />

Define Ion Size:<br />

The size of the ion's atom in comparison to the size of the element atom.<br />

Cation<br />

Anions<br />

Explanation:<br />

Cations give up electrons so they go down the energy level so the larger mass means it is<br />

going to pull the energy levels. Since Calcium has little mass it has to give up the electrons.


Unit 3<br />

Chapter 25 Nuclear Chemistry<br />

The students will learn what happens when an unstable<br />

nucleus decays and how nuclear chemistry affects their lives.<br />

Explore the theory of electromagnetism by comparing and contrasting the<br />

different parts of the electromagnetic spectrum in terms of wavelength,<br />

frequency, and energy, and relate them to phenomena and applications.<br />

Students will be able to compare and contrast the different parts of the<br />

electromagnetic spectrum.<br />

Students will be able to apply knowledge of the EMS to real world phenomena.<br />

Students will be able to quantitatively compare the relationship between energy,<br />

wavelength, and frequency of the EMS.<br />

amplitude<br />

wavelength<br />

frequency<br />

hertz<br />

electromagnetic radiation<br />

photon<br />

Planck’s constant<br />

Explain and compare nuclear reactions (radioactive decay, fission and<br />

fusion), the energy changes associated with them and their associated<br />

safety issues.<br />

Students will be able to compare and contrast fission and fusion reactions.<br />

Students will be able to complete nuclear decay equations to identify the type of<br />

decay.<br />

Students will participate in activities to calculate half-life.<br />

radioactivity<br />

nuclear radiation<br />

alpha particle<br />

beta particle<br />

gamma ray<br />

positron<br />

½ life<br />

transmutation<br />

fission<br />

fusion<br />

50


Chapter 7<br />

Ionic and Metallic Bonding<br />

The students will learn how ionic compounds form and how<br />

metallic bounding affects the properties of metals.<br />

Compare the magnitude and range of the four fundamental forces<br />

(gravitational, electromagnetic, weak nuclear, strong nuclear).<br />

Students will compare/contrast the characteristics of each fundamental force.<br />

gravity<br />

electromagnetic<br />

strong<br />

weak<br />

Distinguish between bonding forces holding compounds together and other<br />

attractive forces, including hydrogen bonding and van der Waals forces.<br />

Students will be able to compare/contrast traits of ionic and covalent bonds.<br />

Students will be able to compare/contrast basic attractive forces between<br />

molecules.<br />

Students will be able to predict the type of bond or attractive force between<br />

atoms or molecules.<br />

ionic bond<br />

covalent bond<br />

metallic bond<br />

polar covalent bond<br />

hydrogen bond<br />

van der Waals forces<br />

London dispersion forces<br />

Chapter 8<br />

Covalent Bonding<br />

The students will learn how molecular bonding is different<br />

than ionic bonding and electrons affect the shape of a<br />

molecule and its properties.<br />

Interpret formula representations of molecules and compounds in terms of<br />

composition and structure.<br />

Students will be able to interpret chemical formulas in terms of # of atoms.<br />

Students will be able to differentiate between ionic and molecular compounds.<br />

Students will be able to list various VSEPR shapes and identify examples of<br />

each.<br />

Students will be able to predict shapes of various compounds.<br />

Molecule<br />

empirical formula<br />

Atom<br />

Electron<br />

Element<br />

Compound<br />

51


Bryan Vega<br />

Name ____________________<br />

Go to the web site www.darvill.clara.net/emag<br />

1. Click on “How the waves fit into the spectrum” and fill in this table:<br />

>: look out for the<br />

RED words on the web site!<br />

frequency<br />

Low __________, Long wavelength<br />

High frequency, Short ______________<br />

wavelength<br />

Radio Waves<br />

Micro Waves<br />

Infra-Red<br />

Visible Light Ultra-Violent X-Rays<br />

Gamma rays<br />

2. Click on “Radio waves”. They are used for _______________________<br />

communications<br />

3. Click on “Microwaves”. They are used for cooking, mobile _________, phones speed<br />

_______ cameras and _________.<br />

wifi<br />

4. Click on “Infra-red”. These waves are given off by _____ hot _________. objects They are used for remote controls,<br />

cameras in police ____________ helicopters , and alarm systems.<br />

laser<br />

5. Click on “Visible Light”. This is used in ___ players and _______ printers, and for seeing where we’re going.<br />

DVD<br />

6. “UV” stands for “ ________ ultra ___________”. violent This can damage the _________ retina in your eyes, and cause<br />

sunburn and even _______ skin cancer. Its uses include detecting forged ______ bank _______. notes<br />

7. X-rays are used to see inside people, and for _________ airport security.<br />

8. Gamma rays are given off by some ________________<br />

radioactive<br />

substances. We can use them to kill ________<br />

cancer<br />

cells,<br />

which is called R_______________ adiotherapy .<br />

9. My Quiz score is ____%. 100<br />

52


10. Name ________________________________<br />

Go to the web site www.darvill.clara.net/emag<br />

Name How they’re made Uses Dangers<br />

They are made by stars They are used to kill living They are<br />

and radioactive<br />

cancer cells.<br />

dangerous cause<br />

substances.<br />

they damage cells .<br />

Gamma rays<br />

X-Rays<br />

Ultra-Violent<br />

Visible Light<br />

Infra-Red<br />

Micro waves<br />

Radio waves<br />

They are made by stars and They are used to see inside<br />

some types of nebula. people.<br />

They are made by special<br />

lamps.<br />

They are made by things<br />

hot enough to glow.<br />

Infra Red waves are made<br />

by stars, lamps, flames,<br />

yourself, and more<br />

Microwaves are made by<br />

frequency radio waves, and<br />

other types of transmitter.<br />

Radio waves are made by<br />

various types of transmitter<br />

UV light are used for<br />

getting a sun tan, detecting<br />

forged bank notes in shops.<br />

We use light to see things.<br />

They are used foe remote<br />

controls for TVs and video<br />

recorders, and more.<br />

We use microwaves to<br />

cook many types of food.<br />

They are used mainly for<br />

communications.<br />

They can cause<br />

cell damage<br />

and cancer.<br />

UV light can damage<br />

the retina in your<br />

eyes<br />

Too much light can<br />

damage the retina<br />

in your eyes.<br />

The danger is<br />

overheating.<br />

Microwaves is known<br />

to cause cataracts in<br />

your eyes<br />

Radio waves are known<br />

to cause cancer, and<br />

other disorders.<br />

_____ High Frequency _____ Low frequency,<br />

Short wavelength ______ High Wavelength<br />

53


Learning Goal for this section:<br />

Explain and compare nuclear reactions (radioactive decay, fission and<br />

fusion), the energy changes associated with them and their associated<br />

safety issues.<br />

Notes Section:<br />

Nucleus= protons+neutrons<br />

N-1amu-0 / (+,-)<br />

P-1amu-+<br />

E-none- -<br />

Element 10 has 20 isotopes<br />

All living things are made up of carbon<br />

Bottom of periodic table- the mass gets massive<br />

Isotopes are an element or atom that has a diferent mass than neutrons<br />

It becomes stable when the number of protons are equal or similar to the number of neutrons<br />

When the particles are connected to your cells it becomes cancerous<br />

Beta particles have a mass of an electron<br />

You are able to convert neutrons to protons<br />

Unit is AMU for protons and neutrons<br />

Gamma radiation can kill<br />

Gamma radiation is energy<br />

More dense the more the atoms are together<br />

Gamma radiation is associated with radioactive decay<br />

54


The Nucleus<br />

A typical model of the atom is called the Bohr Model, in<br />

honor of Niels Bohr who proposed the structure in 1913. The Bohr atom consists of a central nucleus<br />

composed of neutrons and protons, which is surrounded by electrons which “orbit” around the nucleus.<br />

Protons carry a positive charge of one and have a mass of about 1 atomic mass unit or amu (1 amu =1.7x10-<br />

27 kg, a very, very small number). Neutrons are electrically “neutral” and also have a mass of about 1 amu. In<br />

contrast electron carry a negative charge and have mass of only 0.00055 amu. The number of protons in a<br />

nucleus determines the element of the atom. For example, the number of protons in uranium is 92 and the<br />

number in neon is 10. The proton number is often referred to as Z.<br />

Atoms with different numbers of protons are called elements, and are arranged in the periodic table with<br />

increasing Z.<br />

Atoms in nature are electrically neutral so the number of electrons orbiting the nucleus equals the number of<br />

protons in the nucleus.<br />

Neutrons make up the remaining mass of the nucleus and provide a means to “glue” the protons in place.<br />

Without neutrons, the nucleus would split apart because the positive protons would repel each other. Elements<br />

can have nucleii with different numbers of neutrons in them. For example hydrogen, which normally only has<br />

one proton in the nucleus, can have a neutron added to its nucleus to from deuterium, ir have two neutrons<br />

added to create tritium, which is radioactive. Atoms of the same element which vary in neutron number are<br />

called isotopes. Some elements have many stable isotopes (tin has 10) while others have only one or two. We<br />

express isotopes with the nomenclature Neon-20 or 20 Ne 10, with twenty representing the total number of<br />

neutrons and protons in the atom, often referred to as A, and 10 representing the number of protons (Z).<br />

Alpha Particle<br />

Decay<br />

Alpha decay is a radioactive process in which a<br />

particle with two neutrons and two protons is<br />

ejected from the nucleus of a radioactive atom. The particle is identical to the nucleus of a helium atom.<br />

Alpha decay only occurs in very heavy elements such as uranium, thorium and radium. The nuclei of these<br />

atoms are very “neutron rich” (i.e. have a lot more neutrons in their nucleus than they do protons) which makes<br />

emission of the alpha particle possible.<br />

After an atom ejects an alpha particle, a new parent atom is formed which has two less neutrons and two less<br />

protons. Thus, when uranium-238 (which has a Z of 92) decays by alpha emission, thorium-234 is created<br />

(which has a Z of 90).<br />

Because alpha particles contain two protons, they have a positive charge of two. Further, alpha particles are<br />

very heavy and very energetic compared to other common types of radiation. These characteristics allow alpha<br />

particles to interact readily with materials they encounter, including air, causing many ionizations in a very short<br />

distance. Typical alpha particles will travel no more than a few centimeters in air and are stopped by a sheet of<br />

paper.<br />

55


Beta Particle Decay<br />

Beta decay is a radioactive process in which an electron is emitted from the nucleus of a radioactive<br />

atom Because this electron is from the nucleus of the atom, it is called a beta particle to distinguish it<br />

from the electrons which orbit the atom.<br />

Like alpha decay, beta decay occurs in isotopes which are “neutron rich” (i.e. have a lot more<br />

neutrons in their nucleus than they do protons). Atoms which undergo beta decay are located below<br />

the line of stable elements on the chart of the nuclides, and are typically produced in nuclear reactors.<br />

When a nucleus ejects a beta particle, one of the neutrons in the nucleus is transformed into a proton.<br />

Since the number of protons in the nucleus has changed, a new daughter atom is formed which has<br />

one less neutron but one more proton than the parent. For example, when rhenium-187 decays<br />

(which has a Z of 75) by beta decay, osmium-187 is created (which has a Z of 76). Beta particles<br />

have a single negative charge and weigh only a small fraction of a neutron or proton. As a result, beta<br />

particles interact less readily with material than alpha particles. Depending on the beta particles<br />

energy (which depends on the radioactive atom), beta particles will travel up to several meters in air,<br />

and are stopped by thin layers of metal or plastic.<br />

Positron emission or beta plus decay (β+ decay) is a subtype of radioactive decay called beta decay,<br />

in which a proton inside a radionuclide nucleus is converted into a neutron while releasing a positron<br />

and an electron neutrino (νe). Positron emission is mediated by the weak force.<br />

An example of positron emission (β+ decay) is shown with magnesium-23 decaying into sodium-23:<br />

23 Mg12 → 23 Na11 + e +<br />

Because positron emission decreases proton number relative to neutron number, positron decay<br />

happens typically in large "proton-rich" radionuclides. Positron decay results in nuclear transmutation,<br />

changing an atom of one chemical element into an atom of an element with an atomic number that is<br />

less by one unit.<br />

Positron emission should not be confused with electron emission or beta minus decay (β− decay),<br />

which occurs when a neutron turns into a proton and the nucleus emits an electron and an<br />

antineutrino.<br />

56


Gamma<br />

Radiation<br />

After a decay reaction, the nucleus is often in an<br />

“excited” state. This means that the decay has<br />

resulted in producing a nucleus which still has<br />

excess energy to get rid of. Rather than emitting another beta or alpha particle, this energy is lost by<br />

emitting a pulse of electromagnetic radiation called a gamma ray. The gamma ray is identical in<br />

nature to light or microwaves, but of very high energy.<br />

Like all forms of electromagnetic radiation, the gamma ray has no mass and no charge. Gamma rays<br />

interact with material by colliding with the electrons in the shells of atoms. They lose their energy<br />

slowly in material, being able to travel significant distances before stopping. Depending on their initial<br />

energy, gamma rays can travel from 1 to hundreds of meters in air and can easily go right through<br />

people.<br />

It is important to note that most alpha and beta emitters also emit gamma rays as part of their decay<br />

process. However, their is no such thing as a “pure” gamma emitter. Important gamma emitters<br />

including technetium-99m which is used in nuclear medicine, and cesium-137 which is used for<br />

calibration of nuclear instruments.<br />

Half Life<br />

Half-life is the time required for the quantity of a<br />

radioactive material to be reduced to one-half its<br />

original value.<br />

All radionuclides have a particular half-life, some<br />

of which a very long, while other are extremely<br />

short. For example, uranium-238 has such a<br />

long half life, 4.5x109 years, that only a small fraction has decayed since the earth was formed. In<br />

contrast, carbon-11 has a half-life of only 20 minutes. Since this nuclide has medical applications, it<br />

has to be created where it is being used so that enough will be present to conduct medical studies.<br />

57


The Learning Goal for this assignment is:<br />

Distinguish between bonding forces holding compounds together and other attractive<br />

forces, including hydrogen bonding and van der Waals forces<br />

Introduction to Ionic Compounds<br />

Those molecules that consist of charged ions with opposite charges are called IONIC. These ionic<br />

compounds are generally solids with high melting points and conduct electrical current. Ionic<br />

compounds are generally formed from metal and a non-metal elements. See Ionic Bonding below.<br />

Ionic Compound Example<br />

For example, you are familiar with the fairly benign unspectacular behavior of common white<br />

crystalline table salt (NaCl). Salt consists of positive sodium ions (Na + ) & negative chloride ions (Cl - ).<br />

On the other hand the element sodium is a silvery gray metal composed of neutral atoms which react<br />

vigorously with water or air. Chlorine as an element is a neutral greenish-yellow, poisonous, diatomic<br />

gas (Cl2).<br />

The main principle to remember is that ions are completely different in physical and chemical<br />

properties from the neutral atoms of the elements.<br />

The notation of the + and - charges on ions is very important as it conveys a definite meaning.<br />

Whereas elements are neutral in charge, IONS have either a positive or negative charge depending<br />

upon whether there is an excess of protons (positive ion) or excess of electrons (negative ion).<br />

Formation of Positive Ions<br />

Metals usually have 1-4 electrons in the outer energy level. The electron arrangement of a rare gas is<br />

most easily achieved by losing the few electrons in the newly started energy level. The number of<br />

electrons lost must bring the electron number "down to" that of a prior rare gas.<br />

How will sodium complete its octet?<br />

First examine the electron arrangement of the atom. The atomic number is eleven, therefore, there<br />

are eleven electrons and eleven protons on the neutral sodium atom. Here is the Bohr diagram and<br />

Lewis symbol for sodium:<br />

58


This analysis shows that sodium has only one electron in its outer level. The nearest rare gas is neon<br />

with 8 electron in the outer energy level. Therefore, this electron is lost so that there are now eight<br />

electrons in the outer energy level, and the Bohr diagrams and Lewis symbols for sodium ion and<br />

neon are identical. The octet rule is satisfied.<br />

Ion Charge?<br />

What is the charge on sodium ion as a result of losing one electron? A comparison of the atom and<br />

the ion will yield this answer.<br />

Sodium Atom<br />

Sodium Ion<br />

11 p+ to revert to 11 p + Protons are identical in<br />

12 n an octet 12 n<br />

the atom and ion.<br />

Positive charge is<br />

11 e- lose 1 electron 10 e-<br />

caused by lack of<br />

0 charge + 1 charge<br />

electrons.<br />

Formation of Negative Ions<br />

How will fluorine complete its octet?<br />

First examine the electron arrangement of the atom. The atomic number is nine, therefore, there are<br />

nine electrons and nine protons on the neutral fluorine atom. Here is the Bohr diagram and Lewis<br />

symbol for fluorine:<br />

This analysis shows that fluorine already has seven electrons in its outer level. The nearest rare gas<br />

is neon with 8 electron in the outer energy level. Therefore only one additional electron is needed to<br />

complete the octet in the fluorine atom to make the fluoride ion. If the one electron is added, the Bohr<br />

diagrams and Lewis symbols for fluorine and neon are identical. The octet rule is satisfied.<br />

59


Ion Charge?<br />

What is the charge on fluorine as a result of adding one electron? A comparison of the atom and the<br />

ion will yield this answer.<br />

Fluorine Atom Fluoride Ion *<br />

9 p+ to complete 9 p + Protons are identical in<br />

10 n octet 10 n<br />

9 e- add 1 electron 10 e-<br />

0 charge - 1 charge<br />

the atom and ion.<br />

Negative charge is<br />

caused by excess<br />

electrons<br />

* The "ide" ending in the name signifies a simple negative ion.<br />

Summary Principle of Ionic Compounds<br />

An ionic compound is formed by the complete transfer of electrons from a metal to a nonmetal and<br />

the resulting ions have achieved an octet. The protons do not change. Metal atoms in Groups 1-3<br />

lose electrons to non-metal atoms with 5-7 electrons missing in the outer level. Non-metals gain 1-4<br />

electrons to complete an octet.<br />

Octet Rule<br />

Elemental atoms generally lose, gain, or share electrons with other atoms in order to achieve the<br />

same electron structure as the nearest rare gas with eight electrons in the outer level.<br />

The proper application of the Octet Rule provides valuable assistance in predicting and explaining<br />

various aspects of chemical formulas.<br />

Introduction to Ionic Bonding<br />

Ionic bonding is best treated using a simple<br />

electrostatic model. The electrostatic model<br />

is simply an application of the charge<br />

principles that opposite charges attract and<br />

similar charges repel. An ionic compound<br />

results from the interaction of a positive and<br />

negative ion, such as sodium and chloride in<br />

common salt.<br />

The IONIC BOND results as a balance<br />

between the force of attraction between<br />

opposite plus and minus charges of the ions<br />

and the force of repulsion between similar<br />

negative charges in the electron clouds. In<br />

crystalline compounds this net balance of<br />

forces is called the LATTICE ENERGY.<br />

Lattice energy is the energy released in the<br />

formation of an ionic compound.<br />

60<br />

DEFINITION: The formation of an IONIC<br />

BOND is the result of the transfer of one or<br />

more electrons from a metal onto a nonmetal.


Metals, with only a few electrons in the outer energy level, tend to lose electrons most readily. The<br />

energy required to remove an electron from a neutral atom is called the IONIZATION POTENTIAL.<br />

Energy + Metal Atom ---> Metal (+) ion + e-<br />

Non-metals, which lack only one or two electrons in the outer energy level have little tendency to lose<br />

electrons - the ionization potential would be very high. Instead non-metals have a tendency to gain<br />

electrons. The ELECTRON AFFINITY is the energy given off by an atom when it gains electrons.<br />

Non-metal Atom + e- --- Non-metal (-) ion + energy<br />

The energy required to produce positive ions (ionization potential) is roughly balanced by the energy<br />

given off to produce negative ions (electron affinity). The energy released by the net force of<br />

attraction by the ions provides the overall stabilizing energy of the compound.<br />

Notes Section:<br />

Ion is a charged particle<br />

Caton on the left and antons on the right on the periodic table<br />

Ionic compounds are generally solids with high melting points and conduct electrical current<br />

crystalline compounds this net balance of forces is called the lattice energy<br />

Energy + Metal Atom ---> Metal (+) ion + e-<br />

Non-metal Atom + e- --- Non-metal (-) ion + energy<br />

An ionic compound is formed by the complete transfer of electrons from a metal to a nonmetal and the<br />

resulting ions have achieved an octet.<br />

61


The Learning Goal for this assignment is:<br />

The students will learn how molecular<br />

bonding is different than ionic bonding and electrons affect the shape of a molecule and its properties.<br />

Introduction to Covalent Bonding:<br />

Bonding between non-metals consists of two electrons shared between two atoms. Using the Wave<br />

Theory, the covalent bond involves an overlap of the electron clouds from each atom. The electrons<br />

are concentrated in the region between the two atoms. In covalent bonding, the two electrons shared<br />

by the atoms are attracted to the nucleus of both atoms. Neither atom completely loses or gains<br />

electrons as in ionic bonding.<br />

There are two types of covalent bonding:<br />

1. Non-polar bonding with an equal sharing of electrons.<br />

2. Polar bonding with an unequal sharing of electrons. The number of shared electrons depends on<br />

the number of electrons needed to complete the octet.<br />

NON-POLAR BONDING results when two identical non-metals equally share electrons between<br />

them. One well known exception to the identical atom rule is the combination of carbon and hydrogen<br />

in all organic compounds.<br />

Hydrogen<br />

The simplest non-polar covalent molecule is hydrogen. Each hydrogen<br />

atom has one electron and needs two to complete its first energy level.<br />

Since both hydrogen atoms are identical, neither atom will be able to<br />

dominate in the control of the electrons. The electrons are therefore<br />

shared equally. The hydrogen covalent bond can be represented in a<br />

variety of ways as shown here:<br />

The "octet" for hydrogen is only 2 electrons since the nearest rare gas is<br />

He. The diatomic molecule is formed because individual hydrogen atoms<br />

containing only a single electron are unstable. Since both atoms are<br />

identical a complete transfer of electrons as in ionic bonding is<br />

impossible.<br />

Instead the two hydrogen atoms SHARE both electrons equally.<br />

Oxygen<br />

Molecules of oxygen, present in about 20% concentration in air are<br />

also covalent molecules. See the graphic on the left of the Lewis Dot<br />

Structure.<br />

There are 6 electrons in the outer shell, therefore, 2 electrons are<br />

needed to complete the octet. The two oxygen atoms share a total of<br />

four electrons in two separate bonds, called double bonds.<br />

The two oxygen atoms equally share the four electrons.<br />

62


POLAR BONDING results when two different non-metals unequally share electrons between them.<br />

One well known exception to the identical atom rule is the combination of carbon and hydrogen in all<br />

organic compounds.<br />

The non-metal closer to fluorine in the Periodic Table has a greater tendency to keep its own electron<br />

and also draw away the other atom's electron. It is NOT completely successful. As a result, only<br />

partial charges are established. One atom becomes partially positive since it has lost control of its<br />

electron some of the time. The other atom becomes partially negative since it gains electron some of<br />

the time.<br />

Hydrogen Chloride<br />

Hydrogen Chloride forms a polar covalent molecule. The graphic<br />

on the left shows that chlorine has 7 electrons in the outer shell.<br />

Hydrogen has one electron in its outer energy shell. Since 8<br />

electrons are needed for an octet, they share the electrons.<br />

However, chlorine gets an unequal share of the two electrons,<br />

although the electrons are still shared (not transferred as in ionic<br />

bonding), the sharing is unequal. The electrons spends more of the<br />

time closer to chlorine. As a result, the chlorine acquires a "partial"<br />

negative charge. At the same time, since hydrogen loses the<br />

electron most - but not all of the time, it acquires a "partial" charge.<br />

The partial charge is denoted with a small Greek symbol for delta.<br />

Water<br />

Water, the most universal compound on all of the earth, has the property of<br />

being a polar molecule. As a result of this property, the physical and<br />

chemical properties of the compound are fairly unique.<br />

Dihydrogen Oxide or water forms a polar covalent molecule. The graphic on<br />

the left shows that oxygen has 6 electrons in the outer shell. Hydrogen has<br />

one electron in its outer energy shell. Since 8 electrons are needed for an<br />

octet, they share the electrons.<br />

Notes Section:<br />

1 Count the valence electrons<br />

2 Find the central atom and bond the other atoms to it.<br />

Subtract the number of electrons in the bonds from the total.<br />

Add lone pairs to the terminal atoms. Add lone pairs to the<br />

central atom or double or triple bonds<br />

3 Find the formal charges. Try to get the charges as close to<br />

zero as possible by moving electrons and bonds.<br />

63


C 2 H 6 O Ethanol CH 3 CH 2 O<br />

Step 1<br />

Find valence e- for all atoms. Add them together.<br />

C: 4 x 2 = 8<br />

H: 1 x 6 = 6<br />

O: 6<br />

Total = 20<br />

Step 2<br />

Find octet e- for each atom and add them together.<br />

C: 8 x 2 = 16<br />

H: 2 x 6 = 12<br />

O: 8<br />

Total = 36<br />

Step 3<br />

Subtract Step 1 total from Step 2.<br />

Gives you bonding e-.<br />

36 – 20 = 16e-<br />

Step 4<br />

Find number of bonds by diving the number in step 3 by 2<br />

(because each bond is made of 2 e-)<br />

16e- / 2 = 8 bond pairs<br />

These can be single, double or triple bonds.<br />

Step 5<br />

Determine which is the central atom<br />

Find the one that is the least electronegative.<br />

Use the periodic table and find the one farthest<br />

away from Fluorine or<br />

The one that only has 1 atom.<br />

64


Step 6<br />

Put the atoms in the structure that you think it will<br />

have and bond them together.<br />

Put Single bonds between atoms.<br />

Step 7<br />

Find the number of nonbonding (lone pairs) e-.<br />

Subtract step 3 number from step 1.<br />

20 – 16 = 4e- = 2 lone pairs<br />

Step 8<br />

<strong>Complete</strong> the Octet Rule by adding the lone<br />

pairs.<br />

Then, if needed, use any lone pairs to make<br />

double and triple bonds so that all atoms meet<br />

the Octet Rule.<br />

See Step 4 for total number of bonds.<br />

65


Linear<br />

Molecular Geometry<br />

Orbital Equation Lone Pairs Angle<br />

sp AX 2 None 180<br />

BeCl 2<br />

Cl<br />

Be<br />

Cl<br />

Beryllium dichloride<br />

66<br />

element bond lone pair<br />

C


Trigonal Planar<br />

Molecular Geometry<br />

Orbital Equation Lone Pairs Angle<br />

sp 2 AX 3 None 120<br />

BF 3<br />

Boron<br />

F<br />

Trifloride<br />

B<br />

F<br />

F<br />

element bond lone pair<br />

C<br />

67


Bent<br />

Molecular Geometry<br />

Orbital Equation Lone Pairs Angle<br />

sp 2 AX 2 E 1 116<br />

O 3<br />

O<br />

O<br />

O<br />

Trioxide<br />

element bond lone pair<br />

C<br />

68


Tetrahedral<br />

Molecular Geometry<br />

Orbital Equation Lone Pairs Angle<br />

sp 3 AX 4 None 109.5<br />

PO 4<br />

3-<br />

C<br />

-3<br />

O<br />

Posphate<br />

P<br />

O<br />

O<br />

Tetraoxide<br />

element bond lone pair<br />

C<br />

69


Trigonal Pyramid<br />

Molecular Geometry<br />

Orbital Equation Lone Pairs Angle<br />

Sp 3 Ax 3 E 1 107<br />

PH 3<br />

H<br />

Phophorus<br />

Trihydride<br />

P<br />

H<br />

H<br />

element bond lone pair<br />

C<br />

70


Bent<br />

Molecular Geometry<br />

Orbital Equation Lone Pairs Angle<br />

Sp 3 AX 2 E 2 2 104.5<br />

H 2 O<br />

H<br />

O<br />

H<br />

Dihydrogen Oxide<br />

element bond lone pair<br />

C<br />

71


Trigonal Bi Pyramid<br />

Molecular Geometry<br />

Orbital Equation Lone Pairs Angle<br />

Sp 3 d AX 5 None 120/90<br />

PCl 5<br />

Cl<br />

Cl<br />

Phosporus<br />

Pentachloride<br />

P<br />

Cl Cl Cl<br />

element bond lone pair<br />

C<br />

72


T-Shaped<br />

Molecular Geometry<br />

Orbital Equation Lone Pairs Angle<br />

Sp 3 d Ax 3 E 2 2 90<br />

ClF 3<br />

F<br />

Carbon<br />

Iodine<br />

Trifloride<br />

Cl<br />

F<br />

F<br />

element bond lone pair<br />

C<br />

73


Octahedral<br />

Molecular Geometry<br />

Orbital Equation Lone Pairs Angle<br />

Sp 3 d 2 Ax 6 None 90<br />

SF 6<br />

F<br />

F<br />

S<br />

F<br />

F<br />

Sulfur<br />

Hexafloride<br />

F<br />

F<br />

element bond lone pair<br />

C<br />

74


Square Planar<br />

Molecular Geometry<br />

Orbital Equation Lone Pairs Angle<br />

Sp 3 d 2 Ax 4 E 2 2 90<br />

ICl 4<br />

-<br />

Cl<br />

-<br />

Cl<br />

I<br />

Cl<br />

Iodine<br />

Tetrachloride<br />

Cl<br />

el bond lone pair<br />

C<br />

75


Orbitals Equation Lone Pairs Angle<br />

sp AX2 None 180<br />

sp 2 AX 3 None 120<br />

sp 2 AX2E 1 116<br />

sp 3 AX4 None 109.5<br />

sp 3 AX3E 1 107<br />

sp 3 AX2E2 2 104.5<br />

sp 3 d AX5 None 120/90<br />

sp 3 d AX3E2 2 90<br />

sp 3 d 2 AX6 None 90<br />

sp 3 d 2 AX4E2 2 90<br />

Name<br />

Linear<br />

Trig. Planar<br />

Bent<br />

Tetrahedral<br />

Trig. Pyramid<br />

Bent<br />

Trig. BiPyramid<br />

T-Shaped<br />

Octahedral<br />

Square Planar<br />

76


Name Formula Charge<br />

Dichromate Cr₂O₇ 2-<br />

Sulfate SO₄ 2-<br />

Hydrogen Carbonate HCO₃ 1-<br />

Hypochlorite ClO 1-<br />

Phosphate PO₄ 3-<br />

Nitrite NO₂ 1-<br />

Chlorite ClO₂ 1-<br />

Dihydrogen phosphate H₂PO₄ 1-<br />

Chromate CrO₄ 2-<br />

Carbonate CO₃ 2-<br />

Hydroxide OH 1-<br />

Hydrogen phosphate HPO₄ 2-<br />

Ammonium NH₄ 1+<br />

Acetate C₂H₃O₂ 1-<br />

Perchlorate ClO₄ 1-<br />

Permanganate MnO₄ 1-<br />

Chlorate ClO₃ 1-<br />

Hydrogen Sulfate HSO₄ 1-<br />

Phosphite PO₃ 3-<br />

Sulfite SO₃ 2-<br />

Silicate SiO₃ 2-<br />

Nitrate NO₃ 1-<br />

Hydrogen Sulfite HSO₃ 1-<br />

Oxalate C₂O₄ 2-<br />

Cyanide CN 1-<br />

Hydronium H₃O 1+<br />

Thiosulfate S₂O₃ 2-<br />

77


Chapter 9<br />

Unit 4<br />

Chemical Names and Formulas<br />

The students will learn how the periodic table helps them<br />

determine the names and formulas of ions and compounds.<br />

Chapter 22 Hydrocarbon Compounds<br />

The student will learn how Hydrocarbons are named and the<br />

general properties of Hydrocarbons.<br />

Describe how different natural resources are produced and how their rates<br />

of use and renewal limit availability.<br />

Students will explore local, national, and global renewable and nonrenewable<br />

resources.<br />

Students will explain the environmental costs of the use of renewable and<br />

nonrenewable resources.<br />

Students will explain the benefits of renewable and nonrenewable resources.<br />

Nuclear reactors<br />

Natural gas<br />

Petroleum<br />

Refining<br />

Coal<br />

78


Chapter 23 Functional Groups<br />

The student will learn what effects functional groups have on<br />

organic compounds and how chemical reactions are used in<br />

organic compounds.<br />

Describe the properties of the carbon atom that make the diversity of carbon<br />

compounds possible.<br />

Identify selected functional groups and relate how they contribute to<br />

properties of carbon compounds.<br />

Students will identify examples of important carbon based molecules.<br />

Students will create 2D or 3D models of carbon molecules and explain why this<br />

molecule is important to life.<br />

covalent bond<br />

single bond<br />

double bond<br />

triple bond<br />

monomer<br />

polymer<br />

79


http://www.bbc.co.uk/education/guides/zm9hvcw/revision<br />

Learning Goal:<br />

Describe the properties of the carbon atom that<br />

make the diversity of carbon compounds possible.<br />

Identify selected functional groups and relate how they<br />

contribute to properties of carbon compounds.<br />

Addition of bromine water can be used<br />

as a test for unsaturation.<br />

Alkenes quickly turn bromine water colourless,<br />

while alkanes and cycloalkanes do not.<br />

Indicate the position of the branches with a<br />

number, numbering from the end nearest<br />

the functional group.<br />

The alkanes don't contain a functional group<br />

and so the branches are numbered from<br />

the end that gives the lowest set of<br />

position numbers for the branches.<br />

80


Notes:<br />

The test<br />

that you<br />

gave us<br />

was easy<br />

because<br />

I didn't<br />

have Ronny<br />

and instead<br />

I had a<br />

paper.<br />

81


Unit 5<br />

Chapter 10 Chemical Quantities<br />

The student will learn why the mole is important and how the<br />

molecular formula of a compound can be determined<br />

experimentally.<br />

Chapter 11 Chemical Reactions<br />

The students will learn how chemical reactions obey the law of<br />

conservation of mass and how they can predict the products<br />

of a chemical reaction.<br />

Characterize types of chemical reactions, for example: redox, acid-base,<br />

synthesis, and single and double replacement reactions.<br />

<br />

<br />

<br />

<br />

Students will be able to identify the type of chemical reaction that occurs.<br />

Students will be able to compare/contrast reactants and products of various<br />

types of chemical reactions.<br />

Students will be able to predict the product of various reactants.<br />

Students will be able to write balanced chemical equations for each type of<br />

reaction.<br />

Decomposition<br />

Combustion<br />

Redox<br />

Acid-Base<br />

Synthesis<br />

single-replacement<br />

double-replacement<br />

Differentiate between chemical and nuclear reactions.<br />

Students will compare/contrast chemical and nuclear reactions.<br />

fission<br />

fusion<br />

Pg82


Chapter 12 Stoichiometry<br />

The students will learn how balanced chemical equations are<br />

used in stoichiometric calculations and how to calculate<br />

amounts of reactants and products in a chemical equation.<br />

Apply the mole concept and the law of conservation of mass to calculate<br />

quantities of chemicals participating in reactions.<br />

<br />

<br />

<br />

<br />

<br />

<br />

<br />

<br />

Students will be able to use a balanced equation to determine mole ratios.<br />

Students will be able to apply law of conservation of mass to chemical equations.<br />

Students will be able to calculate empirical and molecular formulas.<br />

Students will be able to calculate the % composition of a compound.<br />

Students will be able to calculate theoretical yield.<br />

Students will be able to calculate % error.<br />

Students will be able to calculate molar mass.<br />

Students will be able to perform stoichiometric calculations, including limiting<br />

reagents.<br />

mole<br />

Avogadro’ s number<br />

molar mass<br />

gram formula mass<br />

Pg83


The Mole<br />

LG:The students will learn how balanced chemical<br />

www.youtube.com/watch?v=AsqEkF7hcII equations are used in stoichiometric calculations and how<br />

www.youtube.com/watch?v=tEn0N4R2dqA to calculate amounts of reactants and products in a<br />

www.youtube.com/watch?v=Pft2CASl0M0 chemical equation. Part<br />

www.youtube.com/watch?v=rwhJklbK8R0<br />

_________<br />

NO<br />

N<br />

O<br />

14.01 16.00<br />

H20m<br />

H2x1=2<br />

01x16=16<br />

18amu=H20<br />

Percent<br />

x <strong>Whole</strong><br />

18gH 2 O=1 move H 2 O = 6.02x10 23 molecules H 2 O<br />

H 2 + O=H 2 O<br />

%= Part divided by whole<br />

The mole(mol)-Sl Base Unit used to measure the amount of a substance<br />

The # of particles -carbon atomsin exactly 12g of pure (-12)<br />

Avogadro's number 6.02 x 10 23<br />

602 000 000 000 000 000 000 000!!!!!!!!!!!!!!!!!!!!!!!!!!!!<br />

3.5dozen roses =?????<br />

2.5mol of roses =?????<br />

90340 23 molecules of H 2 O =????? moles of H 2 O<br />

=????? moles of H atoms<br />

l<br />

3.5 dozen roses l<br />

12 roses<br />

------------------------------------------------<br />

l<br />

l 1 dozen roses<br />

l<br />

= 42 roses<br />

Pg84


www.youtube.com/watch?v=BTRm8PwcZ3U<br />

www.youtube.com/watch?v=F9NkYSKJifs<br />

www.youtube.com/watch?v=xPdqEX_WMjo<br />

Molar Mass<br />

LG:The students will learn how balanced chemical<br />

equations are used in stoichiometric calculations and<br />

how to calculate amounts of reactants and products in a<br />

chemical equation.<br />

H<br />

Elements<br />

Check Periodic table<br />

Mna = 22.99 g/ml<br />

Molecules<br />

1.008<br />

O<br />

16.00<br />

S<br />

32.07<br />

Na<br />

22.99<br />

Add up masses of each atom<br />

H 2 SO 4 :<br />

M H2So4 = 2 x 1.008 + 32.07 + 4 x 16.00<br />

= 98.09 g/ml<br />

M o2 = 2 x 16.00 = 32.00 g/mol<br />

Pg85


LG:The students will learn how chemical reactions obey the law of<br />

conservation of mass and how they can predict the products<br />

of a chemical reaction Categories of Reactions<br />

All chemical reactions can be placed into one of six categories. Here they are, in no<br />

particular order:<br />

1) Synthesis: A synthesis reaction is when two or more simple compounds combine to form a<br />

more complicated one. These reactions come in the general form of:<br />

A+B--->AB<br />

H2+02--->H20<br />

One example of a synthesis reaction is the combination of iron and sulfur to form iron (II) sulfide:<br />

8 Fe + S8 ---> 8 FeS<br />

If two elements or very simple molecules combine with each other, it’s probably a synthesis reaction.<br />

The products will probably be predictable using the octet rule to find charges.<br />

2) Decomposition: A decomposition reaction is the opposite of a synthesis reaction - a<br />

complex molecule breaks down to make simpler ones. These reactions come in the general form:<br />

AB-->A+B<br />

H2O-->H2+O2<br />

One example of a decomposition reaction is the electrolysis of water to make oxygen and hydrogen<br />

gas:<br />

2 H2O ---> 2 H2 + O2<br />

If one compound has an arrow coming off of it, it’s probably a decomposition reaction. The products<br />

will either be a couple of very simple molecules, or some elements, or both.<br />

3) Single displacement: This is when one element trades places with another element in a<br />

compound. These reactions come in the general form of:<br />

A+BC-->AC+B<br />

One example of a single displacement reaction is when magnesium replaces hydrogen in water to<br />

make magnesium hydroxide and hydrogen gas:<br />

Mg + 2 H2O ---> Mg(OH)2 + H2<br />

If a pure element reacts with another compound (usually, but not always, ionic), it’s probably a single<br />

displacement reaction. The products will be the compounds formed when the pure element switches<br />

places with another element in the other compound.<br />

Important note: these reactions will only occur if the pure element on the reactant side of the equation<br />

is higher on the activity series than the element it replaces.<br />

Pg86


4) Double displacement: This is when the anions and cations of two different molecules<br />

switch places, forming two entirely different compounds. These reactions are in the general form:<br />

AB+CD-->AD+CB<br />

One example of a double displacement reaction is the reaction of lead (II) nitrate with potassium<br />

iodide to form lead (II) iodide and potassium nitrate:<br />

Pb(NO3)2 + 2 KI ---> PbI2 + 2 KNO3<br />

If two ionic compounds combine, it’s probably a double displacement reaction. Switch the cations<br />

and balance out the charges to figure out what will be made.<br />

Important note: These reactions will only occur if both reactants are soluble in water and only one<br />

product is soluble in water.<br />

5) Acid-base: This is a special kind of double displacement reaction that takes place when an<br />

acid and base react with each other. The H + ion in the acid reacts with the OH - ion in the base,<br />

causing the formation of water. Generally, the product of this reaction is some ionic salt and water:<br />

HA+BOH-->AB+H2O<br />

One example of an acid-base reaction is the reaction of hydrobromic acid (HBr) with sodium<br />

hydroxide:<br />

HBr + NaOH ---> NaBr + H2O<br />

If an acid and a base combine, it’s an acid-base reaction. The products will be an ionic compound<br />

and water.<br />

6) Combustion: A combustion reaction is when oxygen combines with another compound to<br />

form water and carbon dioxide. These reactions are exothermic, meaning they produce heat. An<br />

example of this kind of reaction is the burning of napthalene:<br />

C10H8 + 12 O2 ---> 10 CO2 + 4 H2O<br />

If something that has carbon and hydrogen reacts with oxygen, it’s probably a combustion reaction.<br />

The products will be CO2 and H2O. CH+O2-->H2O + CO<br />

Follow this series of questions. When you can answer "yes" to a question, then<br />

stop!<br />

1) Does your reaction have two (or more) chemicals combining to form one chemical? If yes, then it's<br />

a synthesis reaction<br />

2) Does your reaction have one large molecule falling apart to make several small ones? If yes, then<br />

it's a decomposition reaction<br />

3) Does your reaction have any molecules that contain only one element? If yes, then it's a single<br />

displacement reaction<br />

4) Does your reaction have water as one of the products? If yes, then it's an acid-base reaction<br />

5) Does your reaction have oxygen as one of it's reactants and carbon dioxide and water as<br />

products? If yes, then it's a combustion reaction<br />

6) If you haven't answered "yes" to any of the questions above, then you've got a double<br />

displacement reaction.<br />

Pg 87


List what type the following reactions are:<br />

1) NaOH + KNO3 --> NaNO3 + KOH<br />

Double Displacement<br />

2) CH4 + 2 O2 --> CO2 + 2 H2O<br />

Combustion<br />

3) 2 Fe + 6 NaBr --> 2 FeBr3 + 6 Na<br />

Single Displacement<br />

4) CaSO4 + Mg(OH)2 --> Ca(OH)2 + MgSO4<br />

Double Displacement<br />

5) NH4OH + HBr --> H2O + NH4Br<br />

Acid-Base<br />

6) Pb + O2 --> PbO2<br />

Synthesis<br />

7) Na2CO3 --> Na2O + CO2<br />

Decomposition<br />

Pg88


Determine the Type of Reaction for each equation.<br />

Then predict the products of each of the following chemical reactions. If a reaction will not occur,<br />

explain why not.<br />

Then Balance the equation.<br />

1) __Ag2SO4 + __NaNO3 2 →2AgNO 3 + Na 2 SO4<br />

2) __NaI 2 + __CaSO4 →<br />

3) __HNO3 + __Ca(OH)2 →<br />

Na 2 SO 4 + CaI 2<br />

Na 1 2<br />

I 1 2<br />

Ca 1<br />

S 1<br />

O 4<br />

2H 2 O+Ca(NO 3 ) 2<br />

H 2 4<br />

N 1 2<br />

Ca 1<br />

O 5 8<br />

Ag 2<br />

S1<br />

O 7 10<br />

Na 1 2<br />

N 1 2<br />

4 2 H<br />

2 N<br />

1 Ca<br />

8 7 O<br />

2 Na<br />

2 I<br />

1 Ca<br />

1 S<br />

4 O<br />

2 1 Ag<br />

1 S<br />

10 7 O<br />

Na 2<br />

2 1 N<br />

4) __CaCO3 →<br />

CaO + CO 2<br />

Ca 1<br />

C 2<br />

O 3<br />

1 Ca<br />

2 C<br />

3 O<br />

5) __AlCl3 + __(NH4)PO4 → AlPO 4 + 3NH 4 Cl Al 1<br />

Cl 3<br />

N 3<br />

H 12<br />

P 1<br />

O 4<br />

6) __Pb + __Fe(NO3)3 → No reaction<br />

Al 1<br />

Cl 1 3<br />

N 1 3<br />

H 4 12<br />

P 1<br />

O 4<br />

7) 2 __C3H6 + 9 __O2 →<br />

6H 2 O + 6CO 2<br />

C 3<br />

H 6<br />

O 2 9<br />

C 1 3<br />

H 2 6<br />

O 3 7 9<br />

8) __Na 2 + __CaSO4 →<br />

Ca + Na 2 SO 4<br />

Na 1 2<br />

Ca 1<br />

S 1<br />

O 4<br />

Na 2<br />

Ca 1<br />

S 1<br />

O 4<br />

Pg89


LG:The students will learn how chemical reactions obey the law of<br />

conservation of mass and how they can predict the products<br />

of a chemical reaction<br />

How to Balance Chemical Equations<br />

A chemical equation is a theoretical or written representation of what happens during a chemical<br />

reaction. The law of conservation of mass states that no atoms can be created or destroyed in a<br />

chemical reaction, so the number of atoms that are present in the reactants has to balance the<br />

number of atoms that are present in the products. Follow this guide to learn how to balance chemical<br />

equations.<br />

Step 1<br />

Write down your given equation. For this example, we will use:<br />

C3H8 + O2 --> H2O + CO2<br />

Step 2<br />

Write down the number of atoms that you have on each side of the equation. Look at the subscripts<br />

next to each atom to find the number of atoms in the equation.<br />

Left side: 3 carbon, 8 hydrogen and 2 oxygen<br />

Right side: 1 carbon, 2 hydrogen and 3 oxygen<br />

Pg90


Step 3<br />

Always leave hydrogen and oxygen for last. This means that you will need to balance the carbon<br />

atoms first.<br />

Step 4<br />

Add a coefficient to the single carbon atom on the right of the equation to balance it with the 3 carbon<br />

atoms on the left of the equation.<br />

C3H8 + O2 --> H2O + 3CO2<br />

The coefficient 3 in front of carbon on the right side indicates 3 carbon atoms just as the subscript 3<br />

on the left side indicates 3 carbon atoms.<br />

In a chemical equation, you can change coefficients, but you should never alter the subscripts.<br />

Pg91


Step 5<br />

Balance the hydrogen atoms next. You have 8 on the left side, so you'll need 8 on the right side.<br />

C3H8 + O2 --> 4H2O + 3CO2<br />

On the right side, we added a 4 as the coefficient because the subscript showed that we already<br />

had 2 hydrogen atoms.<br />

When you multiply the coefficient 4 times the subscript 2, you end up with 8.<br />

Step 6<br />

Finish by balancing the oxygen atoms.<br />

Because we've added coefficients to the molecules on the right side of the equation, the number of<br />

oxygen atoms has changed. We now have 4 oxygen atoms in the water molecule and 6 oxygen<br />

atoms in the carbon dioxide molecule. That makes a total of 10 oxygen atoms.<br />

Add a coefficient of 5 to the oxygen molecule on the left side of the equation. You now have 10<br />

oxygen molecules on each side.<br />

C3H8 + 5O2 --> 4H2O + 3CO2.<br />

The carbon, hydrogen and oxygen atoms are balanced. Your equation is complete.<br />

Pg92


1) ___ 2 NaNO3 + ___ PbO ___ Pb(NO3)2 + ___ Na2O<br />

Na 1<br />

O 3<br />

Pb 1<br />

N 1<br />

x 2 =2<br />

x 2=6+1=7<br />

x 2=2<br />

Na 2<br />

O 7<br />

Pb 1<br />

N 2<br />

2) ___ 6 AgI + ___ Fe2(CO3)3 ___ 2 FeI3 + ___ 3 Ag2CO3<br />

Ag 1x 6 =6<br />

I 1x6 =6<br />

Fe 2<br />

C 3<br />

O 9<br />

Ag 2<br />

I 3x2=6<br />

Fe 1x2=2<br />

C 1x3=3<br />

O3x3=9<br />

3) ___ C2H4O2 + ___ 2 O2 ___ 2 CO2 + ___ 2 H2O<br />

C2<br />

H4<br />

O4x2=8<br />

C1x2=2<br />

H2x2=4<br />

O2x4=8<br />

4) ___ ZnSO4 + ___ Li2CO3 ___ ZnCO3 + ___ Li2SO4<br />

IT'S GOOD ;)<br />

5) ___ V2O5 + ___ 5 CaS ___ 5 CaO + ___ V2S5<br />

V2<br />

O5<br />

Ca1x5=5<br />

S1x5=5<br />

V2<br />

O1x5=5<br />

Ca 1x5=5<br />

S5<br />

Pg93


6) ___ Mn(NO2)2 + ___ BeCl2 ___ Be(NO2)2 + ___ MnCl2<br />

IT'S GOOD ;)<br />

7) ___ 3 AgBr + ___ GaPO4 ___ Ag3PO4 + ___ GaBr3<br />

Ag1x3=3<br />

Br1x3=3<br />

Ga1<br />

P1<br />

O4<br />

Ag3<br />

Br3<br />

Ga1<br />

P1<br />

O4<br />

8) ___ 3 H2SO4 + ___ 2 B(OH)3 __ B2(SO4)3 + ___ 6 H2O<br />

H5x2=10+2=12<br />

S1x3=3<br />

O7x2+2=18<br />

B1x2=2<br />

H2x6=12<br />

S3<br />

O13-18<br />

B2<br />

9) ___ S8 + ___ 8 O2 ___ 8 SO2<br />

S8<br />

O2x8=16<br />

S1x8=8<br />

O2x8=16<br />

10) ___ Fe + ___ 2 AgNO3 ___ Fe(NO3)2 + ___ 2 Ag<br />

Fe1<br />

Ag1x2=2<br />

N1x=2=2<br />

O3x2=6<br />

Fe1<br />

Ag1x2=2<br />

N2<br />

O6<br />

Pg94


1) 2 NaNO3 + PbO Pb(NO3)2 + Na2O<br />

2) 6 AgI + Fe2(CO3)3 2 FeI3 + 3 Ag2CO3<br />

3) C2H4O2 + 2 O2 2 CO2 + 2 H2O<br />

4) ZnSO4 + Li2CO3 ZnCO3 + Li2SO4<br />

5) V2O5 + 5 CaS 5 CaO + V2S5<br />

6) Mn(NO2)2 + BeCl2 Be(NO2)2 + MnCl2<br />

7) 3 AgBr + GaPO4 Ag3PO4 + GaBr3<br />

8) 3 H2SO4 + 2 B(OH)3 B2(SO4)3 + 6 H2O<br />

9) S8 + 8 O2 8 SO2<br />

10) Fe + 2 AgNO3 Fe(NO3)2 + 2 Ag<br />

Additional Notes:<br />

Make sure you multiply instead of divide<br />

Don't look at the answer until you finish<br />

Always double check your work<br />

Always make sure the elements on both sides are the same number<br />

Write out the equation when you are done<br />

Pick the right partner at the beginning of the year :)<br />

Pg 95


The Learning Goal for this assignment is: Apply the mole concept and the law of conservation of mass<br />

to calculate quantities of chemicals participating of chemicals<br />

participating in reactions<br />

Stoichiometry and Balancing Reactions<br />

Stoichiometry is a section of chemistry that involves using relationships between reactants and/or<br />

products in a chemical reaction to determine desired quantitative data. In Greek, stoikhein means<br />

element and metron means measure, so stoichiometry literally translated means the measure of<br />

elements. In order to use stoichiometry to run calculations about chemical reactions, it is important to<br />

first understand the relationships that exist between products and reactants and why they exist, which<br />

require understanding how to balanced reactions.<br />

Balancing<br />

In chemistry, chemical reactions are frequently written as an equation, using chemical symbols. The<br />

reactants are displayed on the left side of the equation and the products are shown on the right, with<br />

the separation of either a single or double arrow that signifies the direction of the reaction. The<br />

significance of single and double arrow is important when discussing solubility constants, but we will<br />

not go into detail about it in this module. To balance an equation, it is necessary that there are the<br />

same number of atoms on the left side of the equation as the right. One can do this by raising the<br />

coefficients.<br />

Reactants to Products<br />

A chemical equation is like a recipe for a reaction so it displays all the ingredients or terms of a<br />

chemical reaction. It includes the elements, molecules, or ions in the reactants and in the products as<br />

well as their states, and the proportion for how much of each particle is create relative to one another,<br />

through the stoichiometric coefficient. The following equation demonstrates the typical format of a<br />

chemical equation:<br />

2Na(s) + 2HCl(aq) → 2NaCl(aq) + H2(g)<br />

In the above equation, the elements present in the reaction are represented by their chemical<br />

symbols. Based on the Law of Conservation of Mass, which states that matter is neither created nor<br />

destroyed in a chemical reaction, every chemical reaction has the same elements in its reactants and<br />

products, though the elements they are paired up with often change in a reaction. In this reaction,<br />

sodium (Na), hydrogen (H), and chloride (Cl) are the elements present in both reactants, so based on<br />

the law of conservation of mass, they are also present on the product side of the equations.<br />

Displaying each element is important when using the chemical equation to convert between<br />

elements.<br />

Stoichiometric Coefficients<br />

In a balanced reaction, both sides of the equation have the same number of elements. The<br />

stoichiometric coefficient is the number written in front of atoms, ion and molecules in a chemical<br />

reaction to balance the number of each element on both the reactant and product sides of the<br />

equation. These stoichiometric coefficients are useful since they establish the mole ratio between<br />

reactants and products. In the balanced equation:<br />

2Na(s)+2HCl(aq)→2NaCl(aq)+H2(g)<br />

Pg96


we can determine that 2 moles of HCl will react with 2 moles of Na(s) to form 2 moles of NaCl(aq) and 1<br />

mole of H2(g). If we know how many moles of Na we start out with, we can use the ratio of 2 moles<br />

of NaCl to 2 moles of Na to determine how many moles of NaCl were produced or we can use the<br />

ration of 1 mole of H2 to 2 moles of Na to convert to NaCl. This is known as the coefficient factor. The<br />

balanced equation makes it possible to convert information about one reactant or product to<br />

quantitative data about another element. Understanding this is essential to solving stoichiometric<br />

problems.<br />

Example 1<br />

Lead (IV) hydroxide and sulfuric acid react as shown below. Balance the reaction.<br />

Solution<br />

___Pb(OH)4 +___H2SO4→___Pb(SO4)2 +___H2O<br />

Start by counting the number of atoms of each element.<br />

Unbalanced<br />

Pb 1 1 Pb<br />

O 8 9 O<br />

H 6 2 H<br />

S 1 2 S<br />

The reaction is not balanced; the reaction has 16 reactant atoms and only 14 product atoms and does<br />

not obey the conservation of mass principle. Stoichiometric coefficients must be added to make the<br />

equation balanced. In this example, there are only one sulfur atom present on the reactant side, so a<br />

coefficient of 2 should be added in front of H2SO4to have an equal number of sulfur on both sides of<br />

the equation. Since there are 12 oxygen on the reactant side and only 9 on the product side, a 4<br />

coefficient should be added in front of H2O where there is a deficiency of oxygen. Count the number<br />

of elements now present on either side of the equation. Since the numbers are the same, the<br />

equation is now balanced.<br />

Pb(OH)4 + 2H2SO4→ Pb(SO4)2 + 4H2O<br />

Balanced<br />

Pb 1 1 Pb<br />

O 8 12 12 9 O<br />

H 6 8 8 2 H<br />

S 1 2 2 2 S<br />

Balancing reactions involves finding least common multiples between numbers of elements present<br />

on both sides of the equation. In general, when applying coefficients, add coefficients to the<br />

molecules or unpaired elements last.<br />

A balanced equation ultimately has to satisfy two conditions.<br />

1. The numbers of each element on the left and right side of the equation must be equal.<br />

2. The charge on both sides of the equation must be equal. It is especially important to pay<br />

attention to charge when balancing redox reactions.<br />

Pg97


Stoichiometry and Balanced Equations<br />

In stoichiometry, balanced equations make it possible to compare different elements through the<br />

stoichiometric factor discussed earlier. This is the mole ratio between two factors in a chemical<br />

reaction found through the ratio of stoichiometric coefficients. Here is a real world example to show<br />

how stoichiometric factors are useful.<br />

Example 2<br />

There are 12 party invitations and 20 stamps. Each party invitation needs 2 stamps to be sent. How<br />

many party invitations can be sent?<br />

Solution<br />

The equation for this can be written as<br />

I+2S→IS2<br />

where<br />

I represent invitations,<br />

S represents stamps, and<br />

IS 2 represents the sent party invitations consisting of one invitation and two stamps.<br />

<br />

Based on this, we have the ratio of 2 stamps for 1 sent invite, based on the balanced equation.<br />

Pg98<br />

Invitations Stamps Party Invitations Sent<br />

In this example are all the reactants (stamps and invitations) used up? No, and this is normally the<br />

case with chemical reactions. There is often excess of one of the reactants. The limiting reagent, the<br />

one that runs out first, prevents the reaction from continuing and determines the maximum amount of<br />

product that can be formed.<br />

Example 3<br />

What is the limiting reagent in this example?<br />

Solution<br />

Stamps, because there was only enough to send out invitations, whereas there were enough<br />

invitations for 12 complete party invitations. Aside from just looking at the problem, the problem can<br />

be solved using stoichiometric factors.<br />

12 I x 1IS2 = 12 IS2 possible<br />

1I<br />

20 S x 1IS2 = 10 IS2 possible<br />

2S


When there is no limiting reagent because the ratio of all the reactants caused them to run out at the<br />

same time, it is known as stoichiometric proportions.<br />

Types of Reactions<br />

There are 6 basic types of reactions.<br />

Combustion: Combustion is the formation of CO2 and H2O from the reaction of a chemical<br />

and O2<br />

Combination (synthesis): Combination is the addition of 2 or more simple reactants to form a<br />

complex product.<br />

Decomposition: Decomposition is when complex reactants are broken down into simpler<br />

products.<br />

Single Displacement: Single displacement is when an element from on reactant switches with<br />

an element of the other to form two new reactants.<br />

Double Displacement: Double displacement is when two elements from on reactants<br />

switched with two elements of the other to form two new reactants.<br />

Acid-Base: Acid- base reactions are when two reactants form salts and water.<br />

Molar Mass<br />

Before applying stoichiometric factors to chemical equations, you need to understand molar mass.<br />

Molar mass is a useful chemical ratio between mass and moles. The atomic mass of each individual<br />

element as listed in the periodic table established this relationship for atoms or ions. For compounds<br />

or molecules, you have to take the sum of the atomic mass times the number of each atom in order to<br />

determine the molar mass.<br />

Example 4<br />

What is the molar mass of H2O?<br />

Solution<br />

Molar mass = 2 × (1.00g/mol) + 1×(16.0g/mol) = 18.0g/mol<br />

Using molar mass and coefficient factors, it is possible to convert mass of reactants to mass of<br />

products or vice versa.<br />

Example 5: Combustion of Propane<br />

Propane (C3H8) burns in this reaction:<br />

C3H8 + 5O2 → 4H2O + 3CO2<br />

If 200 g of propane is burned, how many g of H2Ois produced?<br />

Solution<br />

Steps to getting this answer: Since you cannot calculate from grams of reactant to grams of products<br />

you must convert from grams of C3H8 to moles of C3H8 then from moles of C3H8 to moles of H2O.<br />

Then convert from moles of H2O to grams of H2O.<br />

Pg99


Step 1: 200g C3H8 is equal to 4.54 mol C3H8.<br />

Step 2: Since there is a ratio of 4:1 H2O to C3H8, for every 4.54 mol C3H8 there are 18.18 mol<br />

H2O.<br />

Step 3: Convert 18.18 mol H2O to g H2O 18.18 mol H2O is equal to 327.27 g H2O.<br />

Variation in Stoichiometric Equations<br />

Almost every quantitative relationship can be converted into a ratio that can be useful in data<br />

analysis.<br />

Density<br />

Density (ρ) is calculated as mass/volume. This ratio can be useful in determining the volume of a<br />

solution, given the mass or useful in finding the mass given the volume. In the latter case, the inverse<br />

relationship would be used.<br />

Volume x (Mass/Volume) = Mass<br />

Mass x (Volume/Mass) = Volume<br />

Percent Mass<br />

Percent establishes a relationship as well. A percent mass states how many grams of a mixture are of<br />

a certain element or molecule. The percent X% states that of every 100 grams of a mixture, X grams<br />

are of the stated element or compound. This is useful in determining mass of a desired substance in<br />

a molecule.<br />

Example 6<br />

A substance is 5% carbon by mass. If the total mass of the substance is 10.0 grams, what is the<br />

mass of carbon in the sample? How many moles of carbon are there?<br />

Solution<br />

10 g sample x 5 g carbon = 0.5 g carbon<br />

100 g sample<br />

0.5g carbon x 1 mol carbon = 0.0416 mol carbon<br />

12.0g carbon<br />

Molarity<br />

Molarity (moles/L) establishes a relationship between moles and liters. Given volume and molarity, it<br />

is possible to calculate mole or use moles and molarity to calculate volume. This is useful in chemical<br />

equations and dilutions.<br />

Pg100


Example 7<br />

How much 5M stock solution is needed to prepare 100 mL of 2M solution?<br />

Solution<br />

100 mL of dilute solution (1 L/1000 mL) (2 mol/1L solution) (1 L stock solution/5 mol solution) (1000<br />

ml stock solution/1L stock solution) = 40 mL stock solution.<br />

These ratios of molarity, density, and mass percent are useful in complex examples ahead.<br />

Determining Empirical Formulas<br />

An empirical formula can be determined through chemical stoichiometry by determining which<br />

elements are present in the molecule and in what ratio. The ratio of elements is determined by<br />

comparing the number of moles of each element present.<br />

Example 8<br />

1. Find the molar mass of the empirical formula CH2O.<br />

12.0g C + (1.00g H) * (2H) + 16.0g O = 30.0 g/mol CH2O<br />

2. Determine the molecular mass experimentally. For our compound, it is 120.0 g/mol.<br />

3. Divide the experimentally determined molecular mass by the mass of the empirical formula.<br />

(120.0 g/mol) / (30.0 g/mol) = 3.9984<br />

4. Since 3.9984 is very close to four, it is possible to safely round up and assume that there was a<br />

slight error in the experimentally determined molecular mass. If the answer is not close to a whole<br />

number, there was either an error in the calculation of the empirical formula or a large error in the<br />

determination of the molecular mass.<br />

5. Multiply the ratio from step 4 by the subscripts of the empirical formula to get the molecular<br />

formula.<br />

CH2O * 4 =?<br />

C: 1 * 4 = 4<br />

H: 2 * 4 = 8<br />

O 1 * 4 = 4<br />

CH2O * 4 = C4H8O4<br />

6. Check your result by calculating the molar mass of the molecular formula and comparing it to the<br />

experimentally determined mass.<br />

molar mass of C4H8O4= 120.104 g/mol<br />

experimentally determined mass = 120.056 g/mol<br />

% error = | theoretical - experimental | / theoretical * 100%<br />

% error = | 120.104 g/mol - 120.056 g/mol | / 120.104 g/mol * 100%<br />

% error = 0.040 %<br />

Pg101


Stoichiometry and balanced equations make it possible to use one piece of information to calculate<br />

another. There are countless ways stoichiometry can be used in chemistry and everyday life. Try and<br />

see if you can use what you learned to solve the following problems.<br />

Problem 1<br />

Why are the following equations not considered balanced?<br />

a. H2O(l)→H2(g)+O2(g)<br />

a)If listing each molecule it will be seen that on the on<br />

b. Zn(s)+Au + (aq) →Zn 2+ (aq) +Ag(s) the right there are 2 oxygens while the left has only 1<br />

b)The equation is not changes, it is the same on both<br />

product and rectant<br />

Problem 2<br />

Hydrochloric acid reacts with a solid chunk of aluminum to produce hydrogen gas and aluminum ions.<br />

Write the balanced chemical equation for this reaction.<br />

2Al + 6HCl ---> 3H 2 + AlCl 3<br />

Problem 3<br />

Given a 10.1M stock solution, how many mL must be added to water to produce 200 mL of 5M<br />

solution?<br />

10.1m 1m<br />

5m<br />

200mL<br />

1000mL<br />

=<br />

2020<br />

5000<br />

=.404mL<br />

Problem 4<br />

If 0.502g of methane gas react with 0.27g of oxygen to produce carbon dioxide and water, what is the<br />

limiting reagent and how many moles of water are produced? The unbalanced equation is provided<br />

below.<br />

CH4(g)+O2(g)→CO2(g)+H2O(l)<br />

.502gCH 4<br />

1mCH 4<br />

1mCO 2<br />

44gCO 2<br />

1.38<br />

16gCH 4<br />

1mCH 4<br />

1mCO 2<br />

Limiting reagent is O 2 with product of .37g<br />

.27gO 2<br />

32gO 2<br />

1mO 2<br />

1mO 2<br />

1mCO 2<br />

1mCO 2<br />

44gCO 2<br />

.37125<br />

Pg102


Theoretical and Actual Yields<br />

Key Terms<br />

<br />

<br />

<br />

(Excess reagent, limiting reagent)<br />

Theoretical and actual yields<br />

Percentage or actual yield<br />

Skills to Develop<br />

Use stoichiometric calculation to determine excess and limiting reagents in a chemical reaction<br />

<br />

<br />

and explain why.<br />

Calculate theoretical yields of products formed in reactions that involve limiting reagents.<br />

Evaluate percentage or actual yields from known amounts of reactants<br />

Theoretical and Actual Yields<br />

Reactants not completely used up are called excess reagents, and the reactant that completely<br />

reacts is called the limiting reagent. This concept has been illustrated for the reaction:<br />

2Na+Cl2 →2NaCl<br />

Amounts of products calculated from the complete reaction of the limiting reagent are called<br />

theoretical yields, whereas the amount actually produced of a product is the actual yield. The ratio of<br />

actual yield to theoretical yield expressed in percentage is called the percentage yield.<br />

percent yield = actual yield / theoretical yield ×100<br />

Chemical reaction equations give the ideal stoichiometric relationship among reactants and products.<br />

Thus, the theoretical yield can be calculated from reaction stoichiometry. For many chemical<br />

reactions, the actual yield is usually less than the theoretical yield, understandably due to loss in the<br />

process or inefficiency of the chemical reaction.<br />

Example 1<br />

Methyl alcohol can be produced in a high-pressure reaction<br />

CO(g) + 2H2(g) →CH3OH(l)<br />

If 6.1 metric tons of methyl alcohol is obtained from 1.2 metric tons of hydrogen reacting with excess<br />

amount of CO, estimate the theoretical and the percentage yield?<br />

Hint:<br />

To calculate the theoretical yield, consider the reaction<br />

CO(g) + 2H2(g) → CH3OH(l)<br />

28.0 + 4.0 = 32.0 (stoichiometric masses in, g, kg, or tons)<br />

1.2 tons H2 × 32.0 CH3OH = 9.6 tons CH3OH<br />

4.0 H2<br />

Thus, the theoretical yield from 1.2 metric tons (1.2x10 6 g) of hydrogen gas is 9.6 tons. The actual<br />

yield is stated in the problem, 6.1 metric tons. Thus, the percentage yield is<br />

Pg103


%yield = 6.1 tons × 100 = 64%<br />

9.6tons<br />

Discussion<br />

Due to chemical equilibrium or the mass action law, the limiting reagent may not be completely<br />

consumed. Thus, a lower yield is expected in some cases. Losses during the recovery process of the<br />

product will cause an even lower actual yield.<br />

Example 2<br />

A solution containing silver ion, Ag + , has been treated with excess of chloride ions Cl − . When dried,<br />

0.1234 g of AgCl was recovered. Assuming the percentage yield to be 98.7%, how many grams of<br />

silver ions were present in the solution?<br />

Hint:<br />

The reaction and relative masses of reagents and product are:<br />

The calculation,<br />

Ag + (aq) + Cl − (aq) → AgCl(s)<br />

107.868 + 35.453 = 143.321<br />

0.1234 g AgCl ×107.868 g Ag + =0.09287 g Ag +<br />

143.321g AgCl<br />

shows that 0.1234 g dry AgCl comes from 0.09287g Ag + ions. Since the actual yield is only 98.7%,<br />

the actual amount of Ag + ions present is therefore<br />

0.09287 g Ag + = 0.09409 g Ag +<br />

0.987<br />

Discussion<br />

One can also calculate the theoretical yield of AgCl from the percentage yield of 98.7% to be<br />

0.1234 g AgCl =0.1250 g AgCl<br />

0.987<br />

From 0.1250 g AgCl, the amount of Ag + present is also 0.09409 g.<br />

Stoichiometry - A Review<br />

Skills Taught<br />

<br />

<br />

<br />

<br />

<br />

<br />

<br />

evaluate molecular weight for a given formula<br />

evaluate weight (mass) percentages of elements for a given formula<br />

evaluate amounts (in mass and mole units) produced in a chemical reaction from given<br />

conditions<br />

classify reactions by types: combination, combustion, displacement, formation, etc<br />

determine the chemical formula when weight percentages are given and then evaluate the<br />

mole percentages of elements in the formula<br />

determine the chemical formula when weight percentages are given and molecular weight is<br />

known<br />

determine the amount produced, the actual yield, and other stoichiometry quantities for a given<br />

reaction<br />

Pg104


Review Purposes<br />

<br />

<br />

<br />

<br />

<br />

To get an overall view of stoichiometry.<br />

Apply skills learned to perform quantitative chemical analysis.<br />

Apply theories and rules of chemistry to solve problems.<br />

Assess areas of strength and weakness for review purposes.<br />

Improve problem solving strategy and learning efficiency.<br />

Stoichiometry<br />

STOICHIOMETRY is the quantitative relationship of reactants and products. This unit has been<br />

divided into the following objects. A brief review is given here so that you can get a birds'-eye or<br />

overall view of stoichiometry.<br />

1.Amounts of substances<br />

Express amounts of substance in mass units of g, kg, tons, and convert them to moles,<br />

kilomoles, or millimoles.<br />

2.Chemical formulas<br />

Represent a substance with a formula that reflects its chemical composition, structure, and<br />

bonding; evaluate weight and mole percentages of elements in a substance; and determine<br />

chemical formula by elemental analysis.<br />

3.Reaction features<br />

Define some common features of chemical reactions; classify chemical reactions by common<br />

features such as combination, combustion, decomposition, displacement, and redox reactions.<br />

4.Reaction equations<br />

Express quantitative relationships using chemical reaction equations; evaluate quantities of<br />

reactants and products in a chemical reaction; and solve reaction stoichiometry problems.<br />

5.Excess and limiting reagents<br />

Define excess and limiting reagents; determine excess and limiting reagents in a reaction<br />

mixture; and determine quantities produced in a chemical reaction.<br />

6.Yields<br />

Define theoretical and actual yields due to limiting reagent; apply the concept of limiting<br />

reagent to evaluate theoretical yield; convert actual yield to percentage yields.<br />

Pg105


Use the space provided to write out the steps you take to solve different types of problems.<br />

Use any additional space for notes. These 2 pages should be full when you turn in your notebook.<br />

Steps to solve problems<br />

Mole to Mole:<br />

(1) In the equation: _H^2+_O^2 -> _H^2O , If you are given 6<br />

moLs of H^2, how many moLs of O^2 will react with it?<br />

1. Balance the equation: _2_H^2+ _1_O^2 -> _2_H^2O<br />

2. Take what you are given and convert to what you need it to<br />

be through the balanced equation<br />

3. Multiply across the bottom and top<br />

4. Match significant figures: The answer is: 3 moLs of O^2<br />

(1) For the balanced equation shown below, how many moles<br />

of H^2 will be produced by 53.5grams of Al?<br />

_2_Al+_3_H^2SO^4=>_1_Al^2(SO^4)^3+_3_H^2<br />

1. Take what you are given and convert to what you need it to be<br />

through mole:mole<br />

and mole:mass ratios<br />

2. Take the grams and figure out the molar mass of the compound, so<br />

you know how much is 1 moL<br />

Al = 27amu, therefore, 27g of Al = 1 moL Al<br />

3. Convert the given mass to moLs through the balanced equation<br />

4. Now convert to the unit that you want to end with (in this case,<br />

moLs of H^2)<br />

5. Multiply across the top and the bottom and then divide to find the<br />

amount you're looking for in moLs<br />

6. Apply significant figures<br />

The answer would be: 2.97 moLs of H^2<br />

Pg106


Moles to Mass: (*in a balanced equation, everything on both<br />

sides is equal to each other as a ratio)<br />

(1) For the balanced equation shown below, how many grams<br />

of S reacted, if 0.147moles of Al^2S^3 are produced?<br />

_2_Al+_3_S=>_1_Al^2S^3<br />

1. Take the amount you are given and convert to moLs of the<br />

desired element<br />

2. Take the moLs of the substance you've converted to, and<br />

turn those into grams<br />

3.Multiply across the top and the bottom<br />

4.Apply significant figures<br />

The answer is : 14.1 g of S<br />

(1) For the balanced equation shown below, how many grams<br />

of Al will react with 12.4 grams of Al2O3?_2_Al<br />

+_3_MnO=>_1_Al^2O^3+_3_Mn<br />

1. Take the amount you are given and convert to the moLs of<br />

the compound<br />

to the amount of the element you have<br />

2.Convert to the desired element/compound through mole:mole<br />

ratios (in this case, to moLs of Al through the balanced<br />

equation)<br />

3.Find the mass of the desired element through conversion of<br />

the mole<br />

4.Multiply across the top and the bottom, then divide.<br />

Pg107


Unit 6<br />

Chapter 13 States of Matter<br />

The students will learn what are the factors that determine and<br />

characteristics that distinguish gases liquids and solids and<br />

how substances change from one state to another.<br />

Differentiate among the four states of matter.<br />

Students will measure the physical characteristics of matter such as temperature<br />

and density.<br />

Students will compare and contrast the physical characteristics of the 4 states of<br />

matter.<br />

solid<br />

liquid<br />

gas<br />

plasma<br />

Relate temperature to the average molecular kinetic energy.<br />

Students will be able to compare and contrast the motion of particles of a sample<br />

at various temperatures.<br />

Kinetic energy<br />

Kinetic theory<br />

Temperature<br />

Describe phase transitions in terms of kinetic molecular theory.<br />

Students will be able to identify and describe phase changes.<br />

Students will be able to compare and contrast the change in particle motion<br />

for phase changes.<br />

Students will be able to interpret heating/cooling curves and phase diagrams.<br />

melting point<br />

freezing point<br />

boiling point<br />

condensation<br />

sublimation<br />

phase diagram<br />

kinetic molecular theory<br />

Pg108


Chapter 14 The Behavior of Gases<br />

The students will learn how gases respond to changes in<br />

pressure, volume, and temperature and why the ideal gas law<br />

is useful even though ideal gases do not exist.<br />

Interpret the behavior of ideal gases in terms of kinetic molecular theory.<br />

Students will be able to describe the behavior of an ideal gas.<br />

Students will participate in activities to apply the Ideal Gas Law and its<br />

component laws to predict gas behavior.<br />

Students will be able to perform temperature/pressure conversions.<br />

Compressibility<br />

Boyle’s Law<br />

Charles’s Law<br />

Gay-Lussac’s Law<br />

Combine Gas Law<br />

Ideal Gas Law<br />

Partial pressure<br />

Dalton’s Law of partial pressure<br />

Diffusion<br />

Effusion<br />

Graham’s Law of effusion<br />

Chapter 15 Water and Aqueous Systems<br />

The students will learn how the interactions between water<br />

molecules account for the unique properties of water and how<br />

aqueous solutions form.<br />

Discuss the special properties of water that contribute to Earth's suitability<br />

as an environment for life: cohesive behavior, ability to moderate<br />

temperature, expansion upon freezing, and versatility as a solvent.<br />

Students will be able to prepare a solution of known molarity<br />

Students will participate in activities to calculate molarity<br />

Surface tension<br />

Surfactant<br />

Aqueous solutionSolvent<br />

Solute<br />

Pg109


The Learning Goal for this assignment is: Differentiate among the 4 states<br />

of matter<br />

Take note over the following chapter. Use the Headings provided to organize your notes. Define and<br />

number all highlighted vocabulary (total 23 ) as well as summarize the sections. You may add pictures<br />

where needed. The pictures should be an appropriate size. Use Arial 12 for all text. This document<br />

should be 3 pages and should be saved as a pdf before you submit it into Angel.<br />

Chapter 13 States of Matter<br />

Pages 420 - 439<br />

13.1 The Nature of Gases<br />

Kinetic Theory and a Model for Gases<br />

The energy an object has because of its motion is called<br />

kinetic energy 1 . According to the kinetic theory 2 , all matter<br />

consists of tiny particles that are in constant motion. The<br />

particles in a gas are considered to be small, hard spheres with an insignificant volume. Within a gas,<br />

the particles are relatively far apart compared with the distance between particles in a liquid or solid.<br />

The motion of the particles in a gas is rapid, constant, and random. As a result, gases fill their<br />

containers regardless of the shape and volume of the containers. All collisions between particles in a<br />

gas are perfectly elastic. During an elastic collision, kinetic energy is transferred without loss from one<br />

particle to another.<br />

Gas Pressure<br />

Gas pressure 3 results from the force exerted by a gas per unit surface area of an object. An empty<br />

space with no particles and no pressure is called a vacuum 4 . The collisions of atoms and molecules<br />

in air with objects results in atmospheric pressure 5 . A barometer 6 is a device that is used to measure<br />

atmospheric pressure. The SI unit of pressure is the pascal(Pa) 7 . One standard atmosphere(atm) 8 is<br />

the pressure required to support 760 mm of mercury in a mercury barometer at 25 o C. Moving bodies<br />

exert a force when they collide with other bodies. Although a single particle in gas is a moving body,<br />

the force it exerts is extremely small. Gas pressure is the result of billions of rapidly moving particles<br />

in a gas simultaneously colliding with an object. If no particles are present, no collisions can occur.<br />

Consequently, there is no pressure.<br />

Kinetic Energy and Temperature<br />

The particles in any collection of atoms or molecules at a given temperature have a wide range of<br />

kinetic energies. Most of the particles have kinetic energies somewhere in the middle of this range.<br />

Therefore, we use average kinetic energy when discussing the kinetic energy of a collection of<br />

particles in a substance. The Kelvin temperature scale reflects the relationship between temperature<br />

and kinetic energy. The Kelvin temperature of a substance is directly proportional to the average<br />

kinetic energy of the particles of the substance. For example, the particle in helium gas at 200 K have<br />

twice the average kinetic energy as the particles in helium gas at 100K. The effects of temperature on<br />

particle motion in liquids and solids are more complex than in gases.<br />

Pg110


13.2 The Nature of Liquids<br />

A Model of Liquids<br />

These intermolecular attractions keep the particles in a liquid<br />

close together, which is why liquids have a definite volume. The<br />

interplay between the disruptive motions of particles in a liquid<br />

and the attractions among the particles determines the physical<br />

properties of liquids. Intermolecular attractions reduce the<br />

amount of space between the particles in a liquid. Thus liquids<br />

are much denser than gases.<br />

Evaporation<br />

The conversion of a liquid to a gas or vapor is called vaporization 9 . When this conversion occurs at<br />

the surface of a liquid that is not boiling, the process is called evaporation 10 . Most of the molecules in<br />

liquid don’t have enough kinetic energy to overcome the attractive forces and escape into the<br />

gaseous state. During evaporation, only those molecules with a certain minimum kinetic energy can<br />

escape from the surface of the liquid. Even some of the particles that do escape collide with<br />

molecules in the air and rebound back into the liquid. Heating the liquid increases the average kinetic<br />

energy of its particle.<br />

Vapor Pressure<br />

A measure of the force exerted by a gas above a liquid is called vapor pressure 11 . In a system at<br />

constant vapor pressure, a dynamic equilibrium exists between the vapor and the liquid. The system<br />

is in equilibrium because the rate of evaporation of liquid equals the rate of condensation of vapor. At<br />

equilibrium, the particles in the system continue to evaporate and condense, but no net charge occurs<br />

in the number of particles in the liquid or vapor. Eventually, the number of particles condensing will<br />

equal the number of particles vaporizing. The vapor pressure will then remain constant.<br />

Boiling Point<br />

The boiling point 12 (bp) is the temperature at which the vapor pressure of the liquid is just equal to the<br />

external pressure on the liquid. The normal boiling point 13 is defined as the boiling point of a liquid at a<br />

pressure of 101.3 kPa. When a liquid is heated to a temperature at which particles throughout the<br />

liquid have enough kinetic energy to vaporize, the liquid begins to boil. Heating allows a freater<br />

number of particles at the liquid’s surface to overcome the attractive forces that keep them in the<br />

liquid state. The remaining particles in the liquid move faster and faster as they absorb the added<br />

energy. Thus, the average kinetic energy of the particles in the liquid increases and the temperature<br />

of the liquid rises.<br />

Pg111


13.3 The Nature of Solids<br />

A Model of Solids<br />

The melting point 14 (mp) is the temperature at which a<br />

solid changes into a liquid. The freezing point 15 (fp) is<br />

the temperature at which a liquid changes into a solid.<br />

The general properties of solids reflect the orderly<br />

arrangement of their particles and the fixed locations of<br />

their particles. The particles in liquids are relatively free<br />

to move. The particles in solids, however, are not.<br />

These solids are dense and not easy to compress.<br />

Because the particles in solids tend to vibrate about<br />

fixed points, solids do not flow. When you heat a solid,<br />

its particles vibrate more rapidly as their kinetic energy<br />

increases.<br />

Crystal Structure and Unit Cell<br />

In a crystal 16 , the particles are arranged in an orderly, repeating, 3-dimensional pattern called a<br />

crystal lattice. The smallest group of particles within a crystal that retains the geometric shape of the<br />

crystal is known as unit cell 17 . Allotropes 18 are 2 or more different molecular forms of the same<br />

element in the same physical state. An amorphous solid 19 lacks an order internal structure. A glass 20<br />

is a transparent fusion product of inorganic substances that have cooled to a rigid state without<br />

crystallizing. The shape of a crystal reflects the arrangement of the particles within the solid. A crystal<br />

has sides, or faces.<br />

13.4 Changes of State<br />

Sublimation<br />

Ice changes directly to water vapor without melting and passing through the liquid state. The change<br />

of a substance from a solid to a vapor without passing through the liquid state is called sublimation 21 .<br />

Sublimation can occur because solids, like liquids, have a vapor pressure. Sublimation occurs in<br />

solids with vapor pressures that exceed atmospheric pressure at or near room temperature. Iodine is<br />

an example of a substance that undergoes sublimation. Sublimations can occur because solids, like<br />

liquids, have a vapor pressure. The violet-black solid changes into a purple vapor without passing<br />

through a liquid state.<br />

Phase Diagrams<br />

A phase diagram 22 gives the<br />

conditions of temperature and<br />

pressure at which a substance exists<br />

as solid, liquid, or gas (vapor). The<br />

triple point 23 describes the only set of<br />

conditions at which all 3 phases can<br />

exist in equilibrium with one another.<br />

For water, the triple point is a<br />

temperature of 0,0160 o C and a<br />

pressure of 0. 61lPa.The relationships<br />

among the solid, liquid, and vapor<br />

states of a substance in a sealed<br />

container can be represented in a<br />

single graph. The conditions of<br />

pressure and temperature at which 2<br />

phase exist in equilibrium are<br />

indicated on a phase diagram by a line separating the 2 regions representing the phases.<br />

Pg112


LG:The students will learn what are the factors that determine and<br />

characteristics that distinguish gases liquids and solids and<br />

how substances change from one state to another.<br />

Name: Bryan Vega<br />

Name: Ronny Sosa<br />

Grade:<br />

States of Matter Project<br />

You and you lab partner are going to create a study aid in the form of a game for the<br />

information in Chapter 13 States of Matter.<br />

First, each of you, independently from each other, will summarize the chapter on 3<br />

pages of a pdf which will be submitted in Angel by the end of class on Wednesday Feb<br />

22.<br />

Second, you and you lab partner will be given a game platform which you will use for<br />

your questions and answers, either Jeopardy or Kahoot.<br />

Third, you will fill in the information at the bottom of this page with your username,<br />

passwords and/or websites so that you do not forget this and I have a copy in case<br />

anything gets misplaced. This page will be submitted into Angel as a Word Document<br />

on Wednesday February 22 during class.<br />

Fourth, you will use your notes to generate the questions and answers.<br />

Finally you will give me access to your game by putting the website or Game Number<br />

on this page adding this page to your 3 pages of notes and resubmitting it in Angel as<br />

a pdf by the end of the class on Friday Feb 24.<br />

This page is due by the end of class on Wednesday February 22.<br />

This Project is due by the end of class on Friday February 24.<br />

Jeopardy (https://jeopardylabs.com)<br />

Password:<br />

Edit Link:<br />

Play Link:<br />

Kahoot (https://getkahoot.com)<br />

Username:bryanwithay<br />

Email:bryanvegalwths@gmail.com<br />

Password:boss304421<br />

Game PIN: 917416<br />

Pg113


LG:The students will learn how gases respond to changes in<br />

pressure, volume, and temperature and why the ideal gas law<br />

is useful even though ideal gases do not exist.<br />

Temperature<br />

Average Kinetic Energy<br />

Pressure<br />

Volume<br />

Gas laws are there to help predict how changing one of these variables will effect the other 2<br />

If we hold the third one constant it changes the other 2<br />

3 Gas laws-If we change 2 it affects the other one<br />

Pg114


We are hold mass constant and temperature constant the only things changing is pressure and volume<br />

As the volume increases, the pressure decreases<br />

When squeezing a balloon it decreases the volume and the pressure increases<br />

Pg115


When the volume increases, the temperature increases<br />

As the temperature increases so does the volume as long as the pressure stays the same<br />

We have to make an equality<br />

Pg116


The pressure and the temperature increase as the volume is still constant When<br />

the temperature increases so does the pressure as well<br />

This used to be used for pressure cooking<br />

If the pressure is 8 and the temperature is 8 and the pressure on the other side is<br />

4 that means the temperature as too be 4<br />

Pg117


Pg118


Boyle's Law<br />

-<br />

A gas system has initial pressure and volume of 1980 torr and 7730 ml If the<br />

pressure changes to 2.95 atm, what will the resultant volume be in ml?<br />

A gas system has an initial volume of 5140 ml with the pressure unknown.<br />

When the volume changes to 8.79 l the pressure is found to be 2070 torr.<br />

What was the initial pressure in atm? #1<br />

Pg119


Water freezes at<br />

-0 o C<br />

Kelvin at 237 o<br />

K----->C -273<br />

C----K>=+273 o<br />

Pg120


Pg121


Combined gas Law- When we put Boyle's law, Charles' law, and Gay-<br />

Lussac's law together, we come up with the combined gas law<br />

Equation<br />

Question-A closed gas system initially has volume and temperature of 2.49L and<br />

28.00C with the pressure unknown. If the same closed system has values of<br />

0.662atm, 9.75L and 178.0C, what was the initial pressure in atm?<br />

Pg122


Ideal gas laws- A law that describes the relationships between measurable<br />

properties of an ideal gas. The law states that P × V = n × (R) × T, where P is<br />

pressure, V is volume, n is the number of moles of molecules, T is the absolute<br />

temperature, and R is the gas constant (8.314 joules per degree Kelvin or 1.985<br />

calories per degree Celsius).<br />

Equation<br />

Question- A gas system has pressure, volume and moles of 1.63atm,6.15L and<br />

0.206moles, respectively. What is the temperature in K?<br />

Pg123


The Learning Goal for this assignment is: The students will learn how the interactions<br />

between water molecules account for the unique properties of water and how aqueous<br />

solutions form.<br />

Take note over the following chapter. Use the Headings provided to organize your notes. Define and<br />

number all highlighted vocabulary (total 22 ) as well as summarize and take notes over the sections.<br />

You may add pictures where needed. The pictures should be an appropriate size. Use Arial 12 for<br />

all text. This document should be 2 pages and should be saved as a pdf before you submit it into<br />

Angel.<br />

Chapter 15 Water and Aqueous Systems<br />

Pages 488 - 507<br />

15.1 Water and Its Properties<br />

Water in the Liquid State-The inward force, or pull, that tends to minimize the surface area of a<br />

liquid is called surface tension 1 . All liquids have a surface tension, but water’s surface tension is<br />

higher than most. This is why, on some surfaces, water tends to bead up rather than spread out. A<br />

surfactant 2 is any substance that interferes with the hydrogen bonding between water molecules and<br />

thereby reduces surface tension. Soaps and detergents are surfactant.<br />

Water in the Solid State- As water begins to cool, it behaves initially like a typical liquid. It<br />

contracts slightly and its density gradually increases. At 4 o C, the density of water is at its maximum of<br />

1.0000g/cm 3 . When the temperature of the water falls below 4 o C the density of water actually starts to<br />

decrease. Below 4 o C, water no longer behaves like a typical liquid. Ice, which forms at 0 o C. The<br />

structure of ice is a regular open framework of water molecules in a hexagonal arrangement. When<br />

ice melts, the framework collapses.<br />

15.2 Homogeneous Aqueous Systems<br />

Solutions- An aqueous solution 3 is water that contains dissolved substances. Even tap water that<br />

we drink is a solution that contains varying amounts of dissolved minerals and gases. In a solution,<br />

the dissolving medium is the solvent 4 . The dissolved particles in a solution are the solute 5 . A solvent<br />

dissolves the solute, and the solute becomes dispersed in the solvent. Solvents and solutes may be<br />

gases, liquids, or solids. Recall that solutions are homogeneous mixtures. They are also stable<br />

mixtures. Substances that dissolve most readily in water include ionic compounds and polar covalent<br />

compounds. The process by which the positive and negative ions of an ionic solid become<br />

surrounded by solvent molecules is called solvation 6 .<br />

124


Electrolytes and Nonelectrolytes- An electrolyte 7 is a compound that conducts an electric<br />

current when it is an aqueous solution or in the molten core. Conduction of an electric current<br />

requires ions that are mobile and, thus, able to carry charges through a liquid. All ionic compounds<br />

are electrolytes because they dissociate into ions. Barium sulfate is an ionic compound that cannot<br />

conduct an electric current in aqueous solution because it is insoluble, but it can conduct in the<br />

molten core. A nonelectrolyte 8 is a compound that does not conduct an electric current in either an<br />

aqueous solution or the molten state. Many molecular compounds are nonelectrolytes because they<br />

are not composed of ions. Most compounds of carbon, such as table sugar and the alcohol in rubbing<br />

alcohol, are nonelectrolytes. In a solution that contains a strong electrolyte 9 , all or nearly all of the<br />

solute exists as ions. The ions move in solution and conduct an electric current. Most soluble salts,<br />

inorganic acids, and inorganic bases are strong electrolytes. A weak electrolyte 10 conducts an<br />

electric current poorly because only a fraction of the solute in the solution exists as ions. Organic<br />

acids and bases are also examples of weak electrolytes.<br />

Hydrates- The water contained in a crystal is called the water of hydration 11 or water of<br />

crystallization. A compound that contains water of hydration is called a hydrate 12 . A substance that is<br />

anhydrous 13 does not contain water. If a hydrate has a pressure higher than the pressure of water<br />

vapor in the air, the hydrate will lose its water of hydration or effloresce 14 . These hydrates and other<br />

compounds that remove moisture from air called hygroscopic 15 . A desiccant 16 is a substance used to<br />

absorb moisture from the air and create a dry atmosphere. These compounds are deliquescent 17 ,<br />

which means that they remove sufficient water from air to dissolve completely and form solutions.<br />

The forces holding the water molecules in hydrates are not very strong, so the water is easily lost and<br />

regained.<br />

15.3 Heterogeneous Aqueous Systems<br />

Suspensions- In contrast, heterogeneous mixtures are not solutions. A suspension 18 is a mixture<br />

from which particles settle out upon standing. A suspension differs from a solution because the<br />

particles of a suspension are much larger and do not stay suspended indefinitely. Suspensions are<br />

heterogeneous because at least two substances can be clearly identified.<br />

Colloids- A colloid 19 is a heterogeneous mixture containing particles that range in size from 1 nm to<br />

1000nm. The particles are spread, or dispersed, throughout the dispersion medium, which can be<br />

solid, liquid, or gas. The scattering of visible light by colloidal particles is called the Tyndall effect 20 .<br />

The chaotic movement of colloidal particles, which was first observed by the Scottish botanist Robert<br />

Brown (1773-1858), is called Brownian motion 21 . An emulsion 22 is a colloidal dispersion of a liquid in<br />

a liquid. Colloids have particles smaller than those in suspensions and larger than lose in solutions.<br />

Many colloids are cloudy or milky in appearance, like suspensions, when they are concentrated.<br />

Colloids may look clear or almost clear, like solutions, when they are diluted. The important difference<br />

between colloids and solutions and suspensions is in the size of the particles. The first substances to<br />

be identified as a colloid was glue. Other substances that were also colloids were paint, aerosol<br />

spray, and smoke.<br />

125


126<br />

Unit 7<br />

Chapter 16 Solutions<br />

The students will learn what properties are used to describe<br />

the nature of solutions and how to quantify the concentration<br />

of a solution.<br />

Chapter 17 Thermochemistry<br />

The student will learn how energy is converted in a chemical<br />

or physical process and how to determine the amount of<br />

energy is absorbed or released in that process.<br />

Differentiate among the various forms of energy and recognize that they can<br />

be transformed from one form to others.<br />

Students will participate in activities to investigate and describe the<br />

transformation of energy from one form to another (i.e. batteries, food, fuels,<br />

etc.)<br />

Explore the Law of Conservation of Energy by differentiating among open,<br />

closed, and isolated systems and explain that the total energy in an isolated<br />

system is a conserved quantity.<br />

<br />

Students will be able to calculate various energy changes:<br />

o q = mc∆t<br />

o ∆Hfus<br />

o ∆Hmelt<br />

Thermochemistry<br />

Heat<br />

System<br />

Surrounding<br />

Law of conservation of energy<br />

Bond Making is exothermic<br />

Bond Breaking is endothermic<br />

Heat capacity<br />

Specific heat<br />

Calorimetry<br />

Enthalpy<br />

Thermochemical equation<br />

Molar heat of (fusion, solidification,<br />

vaporization, condensation, solution)<br />

Distinguish between endothermic and exothermic chemical processes.<br />

Students will be able to recognize exothermic and endothermic reactions through<br />

experimentation.<br />

Students will participate in activities (Pasco) to create exothermic and<br />

endothermic graphs.<br />

Endothermic<br />

Exothermic


Create and interpret potential energy diagrams, for example: chemical<br />

reactions, orbits around a central body, motion of a pendulum<br />

Students will participate in activities (Pasco) to create exothermic and<br />

endothermic graphs.<br />

Students will be able to interpret exothermic and endothermic reaction graphs.<br />

Potential energy diagram<br />

Thermochemical equations<br />

Chapter 18 Reaction Rates and Equilibrium<br />

The student will learn how the rate of a chemical reaction can<br />

be controlled, what the role of energy is and why some<br />

reactions occur naturally and others do not.<br />

Explain how various factors, such as concentration, temperature, and<br />

presence of a catalyst affect the rate of a chemical reaction.<br />

Students will be able to describe how each factor may affect the rate of a<br />

chemical reaction.<br />

Students will be able to compare the relative effect of each factor on the rate of a<br />

chemical reaction.<br />

Rate<br />

Collision theory<br />

Activation energy<br />

Catalyst<br />

Activated complex<br />

Inhibitor<br />

Explain the concept of dynamic equilibrium in terms of reversible processes<br />

occurring at the same rates.<br />

Students will be able to describe a system in dynamic equilibrium.<br />

Students will be able to describe how factors may affect the equilibrium of a<br />

reaction.<br />

Reversible reaction<br />

Chemical equilibrium<br />

Le Chatelier principle<br />

Explain entropy’s role in determining the efficiency of processes that convert<br />

energy to work.<br />

Students will be able to describe the change in entropy of a reaction.<br />

Students will be able to determine if a reaction is spontaneous<br />

Entropy<br />

Law of disorder<br />

Spontaneous/nonspontaneous reaction<br />

127


The Learning Goal for this assignment is:<br />

The students will learn what properties are used to describe<br />

the nature of solutions and how to quantify the concentration<br />

of a solution.<br />

Defining Concentration<br />

Measures of Concentration<br />

Concentration is defined as the amount of dissolved solute in a given amount of solvent or<br />

solution. There are several terms that describe concentration. Some of these terms are relative;<br />

that is, they can be used only to compare the concentration of one solution to another. Dilute and<br />

concentrated are two such terms. A dilute solution contains less dissolved solute than a<br />

concentrated solution (in equal volumes of solution).<br />

The terms saturated, unsaturated, and supersaturated are terms that describe concentration more<br />

precisely.<br />

<br />

<br />

<br />

<br />

<br />

<br />

Saturated: The maximum amount of solute is dissolved in a given amount of solvent at a<br />

particular temperature. Such solutions are stable.<br />

Unsaturated: Less than the maximum amount of solute is dissolved in a given amount of<br />

solvent at a particular temperature. Such solutions are stable.<br />

Supersaturated: More than the maximum amount of solute is dissolved in a given amount of<br />

solvent at a particular temperature. Such solutions are unstable.<br />

Look at the solubility curve shown below:<br />

128<br />

The solubility of NaNO3 is 86.0 g/100 mL H2O (at 20 °C). If you<br />

prepare a solution of 50.0 g NaNO3 dissolved in 100 mL H2O, an unsaturated solution results<br />

(Point A on the graph).<br />

continue adding NaNO to the solution until 86.0 g are dissolved, a saturated solution results<br />

(Point B).<br />

heat the solution to 50 °C, 113 grams NaNO3 can be dissolved (Point C). When the solution<br />

cools back down to 20 °C, it will be supersaturated (Point D).<br />

Quantifying Concentration<br />

To describe the concentration of a solution even more precisely, various measures of concentration<br />

can be used. Some of the ways concentration can be quantified include calculating the<br />

Mass of solute per solution mass (expressed as a percent or parts per million)<br />

Moles of solute per kilogram solvent (molality)<br />

Mass of solute per liter of solution (grams/liter)<br />

Moles of solute per liter of solution (molarity)


Part 1: Mass Percent<br />

Mass percent (also called percent by mass, weight percent, or percent by weight) compares the<br />

mass of the solute to the entire mass of the solution.<br />

Notes:<br />

Mass percentage is one way of representing the concentration of an element in a compound or a component in a mixture.<br />

Mass percentage is calculated as the mass of a component divided by the total mass of the mixture, multiplied by 100%.<br />

Part 2: Parts per Million<br />

Parts per million (ppm) is another measure of concentration. It is similar to mass percent. But<br />

mass percent indicates the number of grams of solute per 100 g solution. Parts per million<br />

indicates the number of grams of solute per 1,000,000 g solution. This measure of concentration is<br />

often used to express the concentrations of very dilute solutions.<br />

Notes:<br />

This is a way of expressing very dilute concentrations of substances. Just as per cent means out of a hundred,<br />

so parts per million or ppm means out of a million.<br />

Part 3: Molality<br />

Molality (m) is the ratio of the moles of solute to the kilograms of solvent. Note: this is the first<br />

measure of concentration that is concerned with the mass of the solvent, not the mass of the<br />

solution as a whole.<br />

Notes:<br />

The molal unit is not used nearly as frequently as the molar unit. A molality is the number of moles of solute<br />

dissolved in one kilogram of solvent.<br />

Part 4: Grams per Liter<br />

To express the concentration of a solution in grams per liter, you must know the mass of the solute<br />

and the volume of the solution, not just the volume of the solvent.<br />

Notes:<br />

A gram per litre or gram per liter (g/L or g/l) is a unit of measurement of mass concentration that shows how many<br />

grams of a certain substance are present in one litre of a usually liquid or gaseous mixture.<br />

Suppose you wanted to know what the concentration would be before making the solution. Could that<br />

be done? In order to relate the volume or mass of solvent to the volume of solution, you would have<br />

to know the density of the solution. You will see how solution density can be used to calculate<br />

molarity in the next section.<br />

129


Part 5: Molarity<br />

Molarity (M) is the most common measure of concentration. The concentration of most solutions<br />

you see in the lab are expressed in terms of molarity. Just like g/L, molarity calculations require<br />

that you know either the volume or density of the resulting solution.<br />

Notes:<br />

Molarity is the concentration of a solution expressed as the number of moles of solute per litre of solution.<br />

To get the molarity, you divide the moles of solute by the litres of solution.<br />

Using Density to Calculate Molarity<br />

If the volume of the resulting solution is not known, molarity is calculated as follows:<br />

Convert the volume of solvent to grams. (The simulation does this step for you.)<br />

Determine the total mass of the solution (mass of solute + mass of solvent).<br />

Convert the solution mass to volume in milliliters, using its density (volume = mass / density).<br />

Convert the solution volume to liters (divide by 1000).<br />

Convert solute grams to moles.<br />

Calculate the molarity (moles solute / L solution).<br />

Reinforcing What You've Learned<br />

1. 35.0 g potassium dichromate are dissolved in 354.0 g distilled water. What is the concentration<br />

of the resulting solution, expressed as percent by mass? 9.00%<br />

2. A chemist discovers that 2587.0 g distilled water are contaminated with 13.0 g NaNO3. What is<br />

the concentration of NaNO3, expressed in ppm? 5.00 X 10 3<br />

3. 175.00 g H2SO4 are added to 61.49 g distilled H2O. What is the molality of the resulting solution?<br />

29.04m<br />

4. 225 g NaBr are dissolved in 525 g distilled water. If the volume of the resulting solution is<br />

584 mL, what is its concentration when expressed in g/L? 385g/L<br />

5. 470.0 g Na2CO3 are dissolved in 4230.0 g distilled water. What is the molarity of the resulting<br />

solution (D = 1.1029 g/mL)? 1.1561 M<br />

Applying What You've Learned<br />

6. Think about the equations for mass percent and parts/million. Consider how you might convert<br />

between these two measures of concentration.<br />

Mass percent = ppm ÷ 10,000 ppm = mass percent X .0001<br />

7. Think about the equations for grams/liter and molarity. Consider how you might convert<br />

between these two measures of concentration.<br />

grams / L = molarity X molar mass<br />

molarity = grams / L ÷ molar mass<br />

130


Glossary<br />

Concentration: Amount of dissolved solute in a given amount of solvent or solution.<br />

Density: Amount of matter per unit volume. Density is calculated by dividing an object's mass by<br />

its volume.<br />

Mass: Amount of matter an object contains or, more scientifically, the measure of an object's<br />

resistance to changes in motion. The SI (Systéme International) unit for mass is the kilogram. In<br />

the lab, mass is often measured in grams.<br />

Mass percent: Also referred to as percent by mass and, occasionally, weight percent or percent<br />

by weight. Mathematically, mass % = (mass of solute / mass of entire solution) x 100.<br />

Molar mass: Mass of a compound, calculated by adding up the individual masses for its component<br />

atoms, which are obtained from the periodic table of the elements. Molar mass is expressed in<br />

grams/mole and is sometimes referred to as molecular mass (for molecular compounds) or formula<br />

mass (for ionic compounds).<br />

Molality (m): Moles of solute per kilogram of solvent. Mathematically, m = moles of solute / kilogram of<br />

solvent.<br />

Molarity (M): Moles of solute per liter of solution. Mathematically, M = moles of solute / liter of<br />

solution.<br />

Mole (mol): Counting unit used to express the large numbers of particles, such as atoms or<br />

molecules, that are involved in chemical processes. One mole of particles contains 6.02 x 10<br />

particles. The mass of one mole of an element, in grams, is equivalent to the atomic mass for that<br />

element, as indicated on the periodic table.<br />

Parts per million (ppm): Measure of concentration often used for dilute solutions. Mathematically,<br />

ppm = (mass of solute / mass of solution) x 10.<br />

Solubility: Measure of the maximum amount of solute that can be dissolved in a given amount of<br />

solvent at a given temperature, forming a stable solution.<br />

Solute: Dissolved substance in a solution. The solute is generally the solution component present<br />

in the lesser amount.<br />

Solution: Homogeneous mixture in which one substance has been dissolved in another.<br />

Solvent: Substance in which a solute is dissolved to form a solution. The solvent is generally the<br />

solution component present in the greater amount.<br />

Volume: Amount of space an object occupies. The SI (Systéme International) unit for volume is<br />

the cubic meter. In the lab, volume is often measured in cubic centimeters, milliliters, or liters.<br />

SAS Curriculum Pathways VLab #866<br />

131


The Learning Goal for this assignment is:<br />

The student will learn how energy is converted in a chemical or physical process and how to<br />

determine the amount of energy is absorbed or released in that process.<br />

The System and the Surroundings in Chemistry<br />

Thermochemistry<br />

The system is the part of the universe we wish to focus our attention on. In the world of chemistry, the<br />

system is the chemical reaction. For example:<br />

2H2 + O2 ---> 2H2O<br />

The system consists of those molecules which are reacting.<br />

The surroundings are everything else; the rest of the universe. For example, say the above reaction is<br />

happening in gas phase; then the walls of the container are part of the surroundings.<br />

There are two important issues:<br />

1. a great majority of our studies will focus on the change in the amount of energy, not the<br />

absolute amount of energy in the system or the surroundings.<br />

2. regarding the direction of energy flow, we have a "sign convention."<br />

Two possibilities exist concerning the flow of energy between system and surroundings:<br />

1. The system can have energy added to it, which increases its amount and lessens the energy<br />

amount in the surroundings.<br />

2. The system can have energy removed from it, thereby lowering its amount and increasing the<br />

amount in the surroundings.<br />

We will signify an increase in energy with a positive sign and a loss of energy with a negative sign.<br />

Also, we will take the point-of-view from the system. Consequently:<br />

1. When energy (heat or work) flow out of the system, the system decreases in its amount. This<br />

is assigned a negative sign and is called exothermic.<br />

2. When energy (heat or work) flows into the system, the system increases its energy amount.<br />

This is assigned a positive sign and is called endothermic.<br />

We do not discuss chemical reactions from the surrounding's point-of-view. Only from the system's.<br />

Notes:<br />

When a reaction occurs, it may either give out energy, in the form of heat, or take in energy.<br />

The amount of energy that is given out or taken in can be measured as the Enthalpy Change of a reaction.<br />

132


Specific Heat<br />

Here is the definition of specific heat:<br />

the amount of heat necessary for 1.00 gram of a substance to change 1.00 °C<br />

Note the two important factors:<br />

1. It's 1.00 gram of a substance<br />

2. and it changes 1.00 °C<br />

Keep in mind the fact that this is a very specific value. It is only for one gram going one degree. The<br />

specific heat is an important part of energy calculations since it tells you how much energy is needed<br />

to move each gram of the substance one degree.<br />

Every substance has its own specific heat and each phase has its own distinct value. In fact, the<br />

specific heat value of a substance changes from degree to degree, but we will ignore that.<br />

The units are often Joules per gram-degree Celsius (J/g*°C). Sometimes the unit J/kg K is also used.<br />

This last unit is technically the most correct unit to use, but since the first one is quite common, you<br />

will need to know both.<br />

I will ignore calorie-based units almost entirely.<br />

Here are the specific heat values for water:<br />

Phase J g¯1 °C¯1 J kg¯1<br />

K¯1<br />

Gas 2.02 2.02 x 10 3<br />

Liquid 4.184 4.184 x 10 3<br />

Solid 2.06 2.06 x 10 3<br />

Notice that one set of values is simply 1000 times bigger than the other. That's to offset the influence<br />

of going from grams to kilograms in the denominator of the unit.<br />

Notice that the change from Celsius to Kelvin does not affect the value. That is because the specific<br />

heat is measured on the basis of one degree. In both scales (Celsius and Kelvin) the jump from one<br />

degree to the next are the same "distance." Sometimes a student will think that 273 must be involved<br />

somewhere. Not in this case.<br />

Specific heat values can be looked up in reference books. Typically, in the classroom, you will not be<br />

asked to memorize any specific heat values. However, you may be asked to memorize the values for<br />

the three phases of water.<br />

As you go about the Internet, you will find different values cited for specific heats of a given<br />

substance. For example, I have seen 4.186 and 4.187 used in place of 4.184 for liquid water. None of<br />

the values are wrong, it's just that specific heat values literally change from degree to degree. What<br />

happens is that an author will settle on one particular value and use it. Often, the one particular value<br />

used is what the author used as a student.<br />

Hence, 4.184.<br />

133


The Time-Temperature Graph<br />

We are going to heat a container that has 72.0 grams of ice (no liquid water yet!) in it. To make the<br />

illustration simple, please consider that 100% of the heat applied goes into the water. There is no loss<br />

of heat into heating the container and no heat is lost to the air.<br />

Let us suppose the ice starts at -10.0 °C and that the pressure is always one atmosphere. We will<br />

end the example with steam at 120.0 °C.<br />

There are five major steps to discuss in turn before this problem is completely solved. Here they are:<br />

1. the ice rises in temperature from -10.0 to 0.00 °C.<br />

2. the ice melts at 0.00 °C.<br />

3. the liquid water then rises in temperature from zero to 100.0 °C.<br />

4. the liquid water then boils at 100.0 °C.<br />

5. the steam then rises in temperature from 100.0 to 120.0 °C<br />

Each one of these steps will have a calculation associated with it. WARNING: many homework and<br />

test questions can be written which use less than the five steps. For example, suppose the water in<br />

the problem above started at 10.0 °C. Then, only steps 3, 4, and 5 would be required for solution.<br />

To the right is the type of graph which is typically used to<br />

show this process over time.<br />

You can figure out that the five numbered sections on the<br />

graph relate to the five numbered parts of the list just above<br />

the graph.<br />

Also, note that numbers 2 and 4 are phases changes: solid<br />

to liquid in #2 and liquid to gas in #4.<br />

Q=mcΔT<br />

where ΔT is (Tf – Ti)<br />

Here are some symbols that will be used, A LOT!!<br />

Δt = the change in temperature from start to finish in degrees Celsius (°C)<br />

m = mass of substance in grams<br />

c = the specific heat. Its unit is Joules per gram X degree Celsius (J / g °C is one way to write<br />

the unit; J g¯1 °C¯1 is another)<br />

q = the amount of heat involved, measured in Joules or kilojoules (symbols = J and kJ)<br />

mol = moles of substance.<br />

ΔH is the symbol for the molar heat of fusion and ΔH is the symbol for the molar heat of<br />

vaporization.<br />

We will also require the molar mass of the substance. In this example it is water, so the molar mass is<br />

18.0 g/mol.<br />

Notes:<br />

When a system adjusts due to a temperature change, there are no sudden changes in<br />

concentration of any species, so there are no vertical lines on the graph.<br />

134


Step One: solid ice rises in temperature<br />

As we apply heat, the ice will rise in temperature until it<br />

arrives at its normal melting point of zero Celsius.<br />

Once it arrives at zero, the Δt equals 10.0 °C.<br />

Here is an important point: THE ICE HAS NOT MELTED<br />

YET.<br />

At the end of this step we have SOLID ice at zero<br />

degrees. It has not melted yet. That's an important point.<br />

Each gram of water requires a constant amount of energy<br />

to go up each degree Celsius. This amount of energy is<br />

called specific heat and has the symbol c.<br />

72.0 grams of ice (no liquid water yet!) has changed 10.0 °C. We need to calculate the energy<br />

needed to do this.<br />

This summarizes the information needed:<br />

Δt = 10 °C<br />

The mass = 72.0 g<br />

c = 2.06 Joules per gram-degree Celsius<br />

The calculation needed, using words & symbols is:<br />

q = (mass) (Δt) (c)<br />

Why is this equation the way it is?<br />

Think about one gram going one degree. The ice needs 2.06 J for that. Now go the second degree.<br />

Another 2.06 J. Go the third degree and use another 2.06 J. So one gram going 10 degrees needs<br />

2.06 x 10 = 20.6 J. Now we have 72 grams, so gram #2 also needs 20.6, gram #3 needs 20.6 and so<br />

on until 72 grams.<br />

With the numbers in place, we have:<br />

q = (72.0 g) (10 °C) (2.06 J/g °C)<br />

So we calculate and get 1483.2 J. We won't bother to round off right now since there are four more<br />

calculations to go. Maybe you can see that we will have to do five calculations and then sum them all<br />

up.<br />

One warning before going on: three of the calculations will yield J as the unit on the answer and two<br />

will give kJ. When you add the five values together, you MUST have them all be the same unit.<br />

In the context of this problem, kJ is the preferred unit. You might want to think about what 1483.2 J is<br />

in kJ.<br />

Notes:<br />

As we apply heat, the ice will rise in temperature until it arrives at its normal melting point of zero<br />

Celsius.Each gram of water requires a constant amount of energy to go up each degree Celsius. This<br />

amount of energy is called specific heat and has the symbol c.<br />

135


Step Two: solid ice melts<br />

Now, we continue to add energy and the ice begins to<br />

melt.<br />

However, the temperature DOES NOT CHANGE. It<br />

remains at zero during the time the ice melts.<br />

Each mole of water will require a constant amount of<br />

energy to melt. That amount is named the molar heat of<br />

fusion and its symbol is ΔHf. The molar heat of fusion is<br />

the energy required to melt one mole of a substance at its<br />

normal melting point. One mole of solid water, one mole<br />

of solid benzene, one mole of solid lead. It does not<br />

matter. Each substance has its own value.<br />

During this time, the energy is being used to overcome water molecules' attraction for each other,<br />

destroying the three-dimensional structure of the ice.<br />

The unit for this is kJ/mol. Sometimes you see older references that use kcal/mol. The conversion<br />

between calories and Joules is 4.184 J = 1.000 cal.<br />

Sometimes you also see this number expressed "per gram" rather than "per mole." For example,<br />

water's molar heat of fusion is 6.02 kJ/mol. Expressed per gram, it is 334.16 J/g.<br />

Typically, the term "heat of fusion" is used with the "per gram" value.<br />

72.0 grams of solid water is 0.0 °C. It is going to melt AND stay at zero degrees. This is an important<br />

point. While the ice melts, its temperature will remain the same. We need to calculate the energy<br />

needed to do this.<br />

This summarizes the information needed:<br />

ΔHf = 6.02 kJ/mol<br />

The mass = 72.0 g<br />

The molar mass of H2O = 18.0 gram/mol<br />

The calculation needed, using words & symbols is:<br />

q = (moles of water) (ΔHf)<br />

We can rewrite the moles of water portion and make the equation like this:<br />

q = (grams water / molar mass of water) (ΔHf)<br />

Why is this equation the way it is?<br />

Think about one mole of ice. That amount of ice (one mole or 18.0 grams) needs 6.02 kilojoules of<br />

energy to melt. Each mole of ice needs 6.02 kilojoules. So the (grams water / molar mass of water) in<br />

the above equation calculates the amount of moles.<br />

With the numbers in place, we have:<br />

q = (72.0 g / 18.0 g mol¯1 ) (6.02 kJ / mol)<br />

So we calculate and get 24.08 kJ. We won't bother to round off right now since there are three more<br />

calculations to go. We're doing the second step now. When all five are done, we'll sum them all up.<br />

136


Step Three: liquid water rises in temperature<br />

Once the ice is totally melted, the temperature can now<br />

begin to rise again.<br />

It continues to go up until it reaches its normal boiling<br />

point of 100.0 °C.<br />

Since the temperature went from zero to 100, the Δt is<br />

100.<br />

Here is an important point: THE LIQUID HAS NOT<br />

BOILED YET.<br />

At the end of this step we have liquid water at 100 degrees. It has not turned to steam yet.<br />

Each gram of water requires a constant amount of energy to go up each degree Celsius. This amount<br />

of energy is called specific heat and has the symbol c. There will be a different value needed,<br />

depending on the substance being in the solid, liquid or gas phase.<br />

72.0 grams of liquid water is 0.0 °C. It is going to warm up to 100.0 °C, but at that temperature, the<br />

water WILL NOT BOIL. We need to calculate the energy needed to do this.<br />

This summarizes the information needed:<br />

Δt = 100.0 °C (100.0 °C – 0.0 °C)<br />

The mass = 72.0 g<br />

c = 4.184 Joules per gram-degree Celsius<br />

The calculation needed, using words & symbols is:<br />

q = (mass) (Δt) (c)<br />

Why is this equation the way it is?<br />

Think about one gram going one degree. The liquid water needs 4.184 J for that. Now go the second<br />

degree. Another 4.184 J. Go the third degree and use another 4.184 J. So one gram going 100<br />

degrees needs 4.184 x 100 = 418.4 J. Now we have 72 grams, so gram #2 also needs 418.4, gram<br />

#3 needs 418.4 and so on until 72 grams.<br />

With the numbers in place, we have:<br />

q = (72.0 g) (100.0 °C) (4.184 J/g °C)<br />

So we calculate and get 30124.8 J. We won't bother to round off right now since there are two more<br />

calculations to go. We will have to do five calculations and then sum them all up.<br />

Notes:<br />

THE LIQUID HAS NOT BOILED YET.Each gram of water requires a constant amount of energy to go up<br />

each degree Celsius. This amount of energy is called specific heat and has the symbol c. There will be a<br />

different value needed, depending on the substance being in the solid, liquid or gas phase.<br />

137


Step Four: liquid water boils<br />

Now, we continue to add energy and the water begins to<br />

boil.<br />

However, the temperature DOES NOT CHANGE. It<br />

remains at 100 during the time the water boils.<br />

Each mole of water will require a constant amount of<br />

energy to boil. That amount is named the molar heat of<br />

vaporization and its symbol is ΔH. The molar heat of<br />

vaporization is the energy required to boil one mole of a<br />

substance at its normal boiling point. One mole of liquid water, one mole of liquid benzene, one mole<br />

of liquid lead. It does not matter. Each substance has its own value.<br />

During this time, the energy is being used to overcome water molecules' attraction for each other,<br />

allowing them to move from close together (liquid) to quite far apart (the gas state).<br />

The unit for this is kJ/mol. Sometimes you see older references that use kcal/mol. The conversion<br />

between calories and Joules is 4.184 J = 1.000 cal.<br />

Typically, the term "heat of vaporization" is used with the "per gram" value.<br />

72.0 grams of liquid water is at 100.0 °C. It is going to boil AND stay at 100 degrees. This is an<br />

important point. While the water boils, its temperature will remain the same. We need to calculate the<br />

energy needed to do this.<br />

This summarizes the information needed:<br />

ΔH = 40.7 kJ/mol<br />

The mass = 72.0 g<br />

The molar mass of H2O = 18.0 gram/mol<br />

The calculation needed, using words & symbols is:<br />

q = (moles of water) (ΔH)<br />

We can rewrite the moles of water portion and make the equation like this:<br />

q = (grams water / molar mass of water) (ΔH)<br />

Why is this equation the way it is?<br />

Think about one mole of liquid water. That amount of water (one mole or 18.0 grams) needs 40.7<br />

kilojoules of energy to boil. Each mole of liquid water needs 40.7 kilojoules to boil. So the (grams<br />

water / molar mass of water) in the above equation calculates the amount of moles.<br />

With the numbers in place, we have:<br />

q = (72.0 g / 18.0 g mol¯1 ) (40.7 kJ / mol)<br />

So we calculate and get 162.8 kJ. We won't bother to round off right now since there is one more<br />

calculation to go. We're doing the fourth step now. When all five are done, we'll sum them all up.<br />

138


Step Five: steam rises in temperature<br />

Once the water is completely changed to steam, the<br />

temperature can now begin to rise again.<br />

It continues to go up until we stop adding energy. In this<br />

case, let the temperature rise to 120 °C.<br />

Since the temperature went from 100 °C to 120°C, the Δt<br />

is 20°C.<br />

Each gram of water requires a constant amount of energy<br />

to go up each degree Celsius. This amount of energy is called specific heat and has the symbol c.<br />

There will be a different value needed, depending on the substance being in the solid, liquid or gas<br />

phase.<br />

72.0 grams of steam is 100.0 °C. It is going to warm up to 120.0 °C. We need to calculate the energy<br />

needed to do this.<br />

This summarizes the information needed:<br />

Δt = 20 °C<br />

The mass = 72.0 g<br />

c = 2.02 Joules per gram-degree Celsius<br />

The calculation needed, using words & symbols is:<br />

q = (mass) (Δt) (c)<br />

Why is this equation the way it is?<br />

Think about one gram going one degree. The liquid water needs 2.02 J for that. Now go the second<br />

degree. Another 2.02 J. Go the third degree and use another 2.02 J. So one gram going 20 degress<br />

needs 2.02 x 20 = 44 J. Now we have 72 grams, so gram #2 also needs 44, gram #3 needs 44 and<br />

so on until 72 grams.<br />

I hope that helped.<br />

With the numbers in place, we have:<br />

q = (72.0 g) (20 °C) (2.02 J/g °C)<br />

So we calculate and get 2908.8 J. We won't bother to round off right now since we still need to sum<br />

up all five values.<br />

Notes:<br />

Once the water is completely changed to steam, the temperature can now begin to rise again.<br />

Each gram of water requires a constant amount of energy to go up each degree Celsius. This<br />

amount of energy is called specific heat and has the symbol c. There will be a different value<br />

needed, depending on the substance being in the solid, liquid or gas phase.<br />

139


The following table summarizes the five steps and their results. Each step number is a link back to<br />

the explanation of the calculation.<br />

Converting to kJ gives us this:<br />

1.4832 kJ<br />

24.08 kJ<br />

30.1248 kJ<br />

162.8 kJ<br />

2.9088 kJ<br />

Step q 72.0 g of H2O<br />

1 1483.2 J Δt = 10 (solid)<br />

2 24.08 kJ melting<br />

3 30124.8 J Δt = 100 (liquid)<br />

4 162.8 kJ boiling<br />

5 2908.8 J Δt = 20 (gas)<br />

Summing up gives 221.3968 kJ and proper significant digits gives us 221.4 kJ for the answer.<br />

Notice how all units were converted to kJ before continuing on. Joules is a perfectly fine unit; it's just<br />

that 221,396.8 J is an awkward number to work with. Usually Joules is used for values under 1000,<br />

otherwise kJ is used.<br />

By the way, on other sites you may see kj used for kilojoules. I've also seen Kj used. Both of these<br />

are wrong symbols. kJ is the only correct symbol.<br />

Enthalpy<br />

When a process occurs at constant pressure, the heat evolved (either released or absorbed) is equal<br />

to the change in enthalpy. Enthalpy (H) is the sum of the internal energy (U) and the product of<br />

pressure and volume (PV) given by the equation:<br />

H=U+PV<br />

When a process occurs at constant pressure, the heat evolved (either released or absorbed) is equal<br />

to the change in enthalpy. Enthalpy is a state function which depends entirely on the state<br />

functions T, P and U. Enthalpy is usually expressed as the change in enthalpy (ΔH) for a process<br />

between initial and final states:<br />

ΔH=ΔU+ΔPVΔ<br />

If temperature and pressure remain constant through the process and the work is limited to pressurevolume<br />

work, then the enthalpy change is given by the equation:<br />

ΔH=ΔU+PΔV<br />

Also at constant pressure the heat flow (q) for the process is equal to the change in enthalpy defined<br />

by the equation:<br />

ΔH=q<br />

By looking at whether q is exothermic or endothermic we can determine a relationship between ΔH<br />

and q. If the reaction absorbs heat it is endothermic meaning the reaction consumes heat from the<br />

surroundings so q>0 (positive). Therefore, at constant temperature and pressure, by the equation<br />

above, if q is positive then ΔH is also positive. And the same goes for if the reaction releases heat,<br />

140


then it is exothermic, meaning the system gives off heat to its surroundings, so q


The Learning Goal for this section is:<br />

The student will learn how the rate of a chemical reaction can be controlled, what the role of energy is<br />

and why some reactions occur naturally and others do not.<br />

You are going to answer these 15 questions first in the order they are given to you. This will be a<br />

quiz grade. You are then going to explain the chemical concepts that are used in each question. You<br />

can do this in the order given or group them by concepts. You can use your book or information<br />

found on the internet but all information must be written in your own word. The font needs to be Arial<br />

12. This is due on Monday April 24 by midnight in the drop box. This document should be a 6-<br />

page pdf.<br />

1.B 6.B 11.A<br />

2.C 7.B 12.D<br />

3.C 8.D 13.C<br />

4.D 9.A 14.D<br />

5.A 10.B 15.D<br />

1 This graph represents the change in energy for two laboratory trials of the same reaction.<br />

Which factor could explain the energy difference between the trials?<br />

A Heat was added to trial #2.<br />

B A catalyst was added to trial #2.<br />

C Trial #1 was stirred.<br />

D Trial #1 was cooled.<br />

Explanation: IN the first trial, the amount of energy required for the reaction to take place is more than<br />

the amount in the second trial. A catalyst reduces the activation energy for the reaction to take place.<br />

Collisions only result in a reaction if the particles collide with a certain minimum energy called the<br />

activation energy for the reaction. To increase the rate of a reaction you need to increase the number<br />

of successful collisions. One possible way of doing this is to provide an alternative way for the<br />

reaction to happen which has a lower activation energy.<br />

2 Consider this balanced chemical equation:<br />

Which will increase the rate of the reaction?<br />

A increasing pressure on the reaction<br />

B decreasing concentration of the reactants<br />

C adding a catalyst to the reaction<br />

D decreasing the temperature of the reaction<br />

142<br />

2H2O2 (aq) → 2H2O(l) + O2 (g)


Explanation: With the addition of the catalyst it will allow the amount of energy required to be less<br />

than what it was originally was. Resulting in an increase rate of the reaction.<br />

3 For the reaction<br />

A + (aq) + B — (aq) → AB (s)<br />

Increasing the temperature increases the rate of the reaction. Which is the best explanation for this<br />

happening?<br />

A The pressure increases, which in turn increases the production of products.<br />

B The concentration of reactants increases with an increase in temperature.<br />

C The average kinetic energy increases, so the likelihood of more effective collisions between ions<br />

increases.<br />

D Systems are more stable at high temperatures.<br />

Explanation: When you increase the surface area, more of the substances is exposed to particles<br />

which in turn will increase the collision of particles that cause the reaction. Therefore, this will result in<br />

an increase in the speed of some reactions. Particles can only react when they collide. If you heat a<br />

substance, the particles move faster and so collide more frequently. That will speed up the rate of<br />

reaction. Collisions only result in a reaction if the particles collide with enough energy to get the<br />

reaction started. This minimum energy required is called the activation energy for the reaction.<br />

4 Which statement explains why the speed of some reactions is increased when the surface area of<br />

one or all the reactants is increased?<br />

A increasing surface area changes the electronegativity of the reactant particles<br />

B increasing surface area changes the concentration of the reactant particles<br />

C increasing surface area changes the conductivity of reactant particles<br />

D increasing surface area enables more reactant particles to collide<br />

Explanation: The more finely divided the solid is, the faster the reaction happens. A powdered solid<br />

will normally produce a faster reaction than if the same mass is present as a single lump. The<br />

powdered solid has a greater surface area than the single lump. You are only going to get a reaction<br />

if the particles in the gas or liquid collide with the particles in the solid. Increasing the surface area of<br />

the solid increases the chances of collision taking place. Increasing the number of collisions per<br />

second increases the rate of reaction.<br />

catalyst<br />

C6H6 + Br2 → C6H5Br + HBr<br />

5 Which of the following changes will cause an increase in the rate of the above reaction?<br />

A increasing the concentration of Br2<br />

B decreasing the concentration of C6H6<br />

C increasing the concentration of HBr<br />

D decreasing the temperature<br />

Explanation: The same argument applies whether the reaction involves collision between two<br />

different particles or two of the same particle. In order for any reaction to happen, those particles<br />

must first collide. This is true whether both particles are in solution, or whether one is in solution and<br />

the other a solid. If the concentration is higher, the chances of collision are greater. For many<br />

reactions involving liquids or gases, increasing the concentration of the reactants increases the rate<br />

of reaction. In a few cases, increasing the concentration of one of the reactants may have little<br />

noticeable effect of the rate.<br />

143


2CO + O2 → 2CO2<br />

6 If the above reaction takes place inside a sealed reaction chamber, then which of these procedures<br />

will cause a decrease in the rate of reaction?<br />

A raising the temperature of the reaction chamber<br />

B increasing the volume inside the reaction chamber<br />

C removing the CO2 as it is formed<br />

D adding more CO to the reaction chamber<br />

Explanation: Increasing the pressure of a gas is exactly the same as increasing its concentration. If<br />

you have a given mass of gas, the way you increase its pressure is to squeeze it into a smaller<br />

volume. If you have the same mass in a smaller volume, then its concentration is higher.<br />

Because "RT" is constant as long as the temperature is constant, this shows that the pressure is<br />

directly proportional to the concentration. If you double one, you will also double the other. Increasing<br />

the pressure on a reaction involving reacting gases increases the rate of reaction. Changing the<br />

pressure on a reaction which involves only solids or liquids has no effect on the rate.<br />

7 A catalyst can speed up the rate of a given chemical reaction by<br />

A increasing the equilibrium constant in favor of products.<br />

B lowering the activation energy required for the reaction to occur.<br />

C raising the temperature at which the reaction occurs.<br />

D increasing the pressure of reactants, thus favoring products.<br />

Explanation: Catalysts increase the rate of reaction without being used up. They do this by lowering<br />

the activation energy needed. With a catalyst, more collisions result in a reaction, so<br />

the rate of reaction increases. Different reactions need different catalysts. Another important idea<br />

about catalysts is that they are selective. That is the catalyst doesn't just speed up all reactions, but<br />

only a very particular reaction. This is the key to many chemical transformations. When you only want<br />

to perform a particular chemical change, you look for a catalyst that will speed up that specific<br />

reaction but not others. Enzymes are remarkable in this way. Living biological systems require a<br />

myriad of specific chemical transformations and there is a unique enzyme to catalyze each of them.<br />

8 Which reaction diagram shows the effect of using the appropriate catalyst in a chemical reaction?<br />

A<br />

C<br />

B<br />

D<br />

144


Explanation: Simple energy level diagrams only show the energy levels at the beginning and end of a<br />

reaction. Energy levels change gradually during a reaction, and this can be shown using a curve<br />

between the reactant and product energy levels. This is an exothermic reaction because the energy<br />

level of the reactants is higher than the energy level of the products. However, the energy curve goes<br />

up from the reactants’ energy level to begin with, then drops to the products’ energy level. This is<br />

because many reactions need an input of energy to start the reaction off. This is energy is called<br />

the activation energy. It is represented on an energy level diagram as the difference between the<br />

reactants’ energy level and the top of the curve.<br />

9 H2O2, hydrogen peroxide, naturally breaks down into H2O and O2 over time. MnO2, manganese<br />

dioxide, can be used to lower the energy of activation needed for this reaction to take place and, thus,<br />

increase the rate of reaction. What type of substance is MnO2?<br />

A a catalyst<br />

B an enhancer<br />

C an inhibitor<br />

D a reactant<br />

Explanation: Manganese(IV) oxide is the inorganic compound with the formula MnO2. This blackish<br />

or brown solid occurs naturally as the mineral pyrolite, which is the main ore of manganese and a<br />

component of manganese nodules. The principal use for MnO2 is for dry-cell batteries, such as<br />

the alkaline battery and the zinc-carbon battery. MnO2 is also used as a pigment and as a precursor<br />

to other manganese compounds, such as link=potassium permanganateKMnO4. It is used as<br />

a reagent in organic synthesis, for example, for the oxidation of allylic alcohols. MnO2 in the α<br />

polymorph can incorporate a variety of atoms in the "tunnels" or "channels" between the magnesium<br />

oxide octahedral.<br />

10 When a reaction is at equilibrium and more reactant is added, which of the following changes is<br />

the immediate result?<br />

A The reverse reaction rate remains the same.<br />

B The forward reaction rate increases.<br />

C The reverse reaction rate decreases.<br />

D The forward reaction rate remains the same.<br />

Explanation: Equilibrium means it wants to stay balanced. If you add reactant, the system is<br />

unbalanced. To undo that, the reaction goes in the forward direction to create more product and use<br />

up the reactant - puts the systems back in balance/equilibrium.<br />

11 In which of the following reactions involving gases would the forward reaction be favored by an<br />

increase in pressure?<br />

A A + B ⇄AB<br />

B A + B ⇄ C + D<br />

C 2A + B ⇄ C + 2D<br />

D AC ⇄ A + C<br />

Explanation: A + b ↔ ab -when dealing with pressure, you need to count the number of moles on<br />

both side of the equation. If there is an increase in pressure, the reaction favors the direction with less<br />

number of moles. If there is a decrease in pressure, the reaction will favor the direction with more<br />

moles of molecules. If the pressure is increased, the reaction will favor the side with less number of<br />

moles of molecules, which in this case is the forward reaction.<br />

4HCl(g) + O2(g) ⇄ 2H2O(l) + 2Cl2(g) + 113 kJ<br />

145


12 Which action will drive the reaction to the right?<br />

A heating the equilibrium mixture<br />

B adding water to the system<br />

C decreasing the oxygen concentration<br />

D increasing the system’s pressure<br />

Explanation: If one or more of the reactants is a gas then increasing pressure will effectively increase<br />

the concentration of the reactant molecules and speed up the reaction. So, for gaseous reactants<br />

only, pressure is essentially a concentration factor. Increasing pressure has virtually no effect on<br />

solids or solutions engaged in a chemical reaction. The particles are, therefore on average, closer<br />

together and collisions between the particles will occur more frequently.<br />

NO2(g) + CO(g) ⇄ NO(g) + CO2(g)<br />

13 The reaction shown above occurs inside a closed flask. What action will shift the reaction to the<br />

left?<br />

A pumping CO gas into the closed flask<br />

B raising the total pressure inside the flask<br />

C increasing the NO concentration in the flask<br />

D venting some CO2 gas from the flask<br />

<br />

Explanation: The reactants are favored which causes them to shift to left because there are no<br />

gases present which means no change. The equilibrium will move in such a way that the<br />

pressure increases again. It can do that by producing more gaseous molecules. In this case, the<br />

position of equilibrium will move towards the left-hand side of the reaction.<br />

NH4Cl(s) + heat ⇄ NH3(g) + HCl(g)<br />

14 What kind of change will shift the reaction above to the right to form more products?<br />

A a decrease in total pressure<br />

B an increase in the concentration of HCl<br />

C an increase in the pressure of NH3<br />

D a decrease in temperature<br />

Explanation: Increasing the temperature increases reaction rates because of the disproportionately<br />

large increase in the number of high energy collisions. It is only these collisions (possessing at least<br />

the activation energy for the reaction) which result in a reaction. When you raise the temperature of a<br />

system, the molecules bounce around a lot more. They have more energy. When they bounce around<br />

more, they are more likely to collide. That fact means they are also more likely to combine. When you<br />

lower the temperature, the molecules are slower and collide less. That temperature drop lowers the<br />

rate of the reaction.<br />

15 In a sealed bottle that is half full of water, equilibrium will be attained when water molecules<br />

A cease to evaporate.<br />

B begin to condense.<br />

C are equal in number for both the liquid and the gas phase.<br />

D evaporate and condense at equal rates.<br />

Explanation: At equilibrium, the rate of forward reaction is equal to the rate of backward reaction.<br />

Therefore, when the rate of condensation will become equal to the rate of evaporation equilibrium is<br />

146


attained. When a liquid is in dynamic equilibrium with its vapor phase, the rates of evaporation and<br />

condensation are exactly equal to each other. The vapor pressure of a liquid is the equilibrium<br />

pressure of a vapor above its liquid (or solid); that is, the pressure of the vapor resulting from<br />

evaporation of a liquid (or solid) above a sample of the liquid (or solid) in a closed container.<br />

147


Unit 8<br />

Chapter 19 Acid and Bases<br />

The student will learn what are the different ways chemists<br />

define aids and bases, what the pH of a solution means and<br />

how chemist use acid-base reactions.<br />

Relate acidity and basicity to hydronium and hydroxyl ion concentration and<br />

pH.<br />

<br />

<br />

<br />

Students will be able to use a pH scale to identify substances as acids or bases.<br />

Students will be able to use various equipment (probeware, universal pH, etc.) to<br />

identify the pH of substances.<br />

Students will be able to calculate H3O+ and OH- concentration of various<br />

substances.<br />

pH scale<br />

Hydronium ion<br />

Arrhenius acid/base<br />

Lewis acid/base<br />

Bronsted-Lowry acid/base<br />

Strong acid/base<br />

Weak acid/base<br />

Neutralization reaction<br />

Titration<br />

Chapter 20 Oxidation-Reduction Reactions<br />

The student will learn what happens during oxidation and<br />

reduction and how to balance redox equations.<br />

Describe oxidation-reduction reactions in living and non-living systems.<br />

<br />

<br />

<br />

Students will be able to compare and contrast redox reactions.<br />

Students will be able to assign oxidation numbers to redox reactions.<br />

Students will be able to write half reactions<br />

148<br />

Oxidation


Reduction<br />

Oxidation reduction reaction<br />

Oxidation number<br />

Half reaction<br />

Electrochemical process<br />

Battery<br />

Cathode<br />

Anode<br />

Electrolysis<br />

149


The Learning Goal for this section is:<br />

The student will learn what are the different ways chemists define aids and bases, what the<br />

pH of a solution means and how chemist use acid-base reactions.<br />

Acids and Bases<br />

The Observable Properties of Acids and Bases<br />

The words acid and alkaline (an older word for base) are derived from direct sensory experience.<br />

Acid Property #1:<br />

The word acid comes from the Latin word acere, which means "sour." All acids taste sour. Well<br />

known from ancient times were vinegar, sour milk and lemon juice. Aspirin (scientific name:<br />

acetylsalicylic acid) tastes sour if you don't swallow it fast enough. Other languages derive their word<br />

for acid from the meaning of sour. So, in France, we have acide. In Germany, we have säure from<br />

saure and in Russia, kislota from kisly.<br />

Base Property #1:<br />

The word "base" has a more complex history (see below) and its name is not related to taste. All<br />

bases taste bitter. For example, mustard is a base. It tastes bitter. Many medicines, because they are<br />

bases, taste bitter. This is the reason cough syrups are advertised as having a "great grape taste."<br />

The taste is added in order to cover the bitterness of the active ingredient in cough syrup.<br />

Acid Property #2:<br />

Acids make a blue vegetable dye called litmus turn red.<br />

Base Property #2:<br />

Bases are substances which will restore the original blue color of litmus after having been reddened<br />

by an acid.<br />

Acid Property #3:<br />

Acids destroy the chemical properties of bases.<br />

Base Property #3:<br />

Bases destroy the chemical properties of acids.<br />

Neutralization is the name for this type of reaction.<br />

Acid Property #4:<br />

Acids conduct an electric current.<br />

Base Property #4:<br />

Bases conduct an electric current.<br />

This is a common property shared with salts. Acids, bases and salts are grouped together into a<br />

category called electrolytes, meaning that a water solution of the given substance will conduct an<br />

electric current.<br />

Non-electrolyte solutions cannot conduct a current. The most common example of this is sugar<br />

dissolved in water.<br />

150


So far, the properties have an obvious relationship: taste, color change, mutual destruction, and<br />

response to electric current. This last property is related, but in a less obvious way. The property<br />

below identifies a unique chemical reaction that acids and bases engage in.<br />

Acid Property #5:<br />

Upon chemically reacting with an active metal, acids will evolve hydrogen gas (H2). The key word, of<br />

course, is active. Some metals, like gold, silver or platinum, are rather unreactive and it takes rather<br />

extreme conditions to get these "unreactive" metals to react. Not so with the metals in this property.<br />

They include the alkali metals (Group I, Li to Rb), the alkaline earth metals (Group II, Be to Ra), as<br />

well as zinc and aluminum. Just bring the acid and the metal together at anything close to room<br />

temperature and you get a reaction. Here's a sample reaction:<br />

Zn + 2 HCl(aq) ---> ZnCl2 + H2<br />

Another common acid reaction some sources mention is that acids react with carbonates (and<br />

bicarbonates) to give carbon dioxide gas:<br />

HCl + NaCO3 ---> CO2 + H2O + NaCl<br />

Base Property #5:<br />

Bases feel slippery, sometimes people say soapy. This is because they dissolve the fatty acids and<br />

oils from your skin and this cuts down on the friction between your fingers as you rub them together.<br />

In essence, the base is making soap out of you. Yes, bases are involved in the production of soap! In<br />

the early years of soap making, the soaps were very harsh on the skin and clothes due to the high<br />

base content. Even today, people with very sensitive skin must sometimes use a non-soap-based<br />

product for bathing.<br />

It was not until more modern times that the chemical nature (as opposed to observable properties) of<br />

acids and bases began to be explored. That leads to this property that is not directly observable by<br />

the senses.<br />

Acid Property #6:<br />

Acids produce hydrogen ion (H + ) in solution. A more correct formula for what is produced is that of the<br />

hydronium ion, H3O + . Both formulas are used interchangeably.<br />

Acid base theories: Svante Arrhenius<br />

I. Introduction<br />

The basic idea is that certain substances remain ionized in solution all the time. Today, everyone<br />

accepts this without question, but it was the subject of much dissention and disagreement in 1884,<br />

when a twenty-five-year-old Arrhenius presented and defended his dissertation.<br />

II. The Acid Base Theory<br />

Acid - any substance which delivers hydrogen ion (H + ) to the solution.<br />

Base - any substance which delivers hydroxide ion (OH¯) to the solution.<br />

Here is a generic acid dissociating, according to Arrhenius:<br />

HA ---> H + + A¯<br />

151


This would be a generic base:<br />

152<br />

XOH ---> X + + OH¯<br />

When acids and bases react according to this theory, they neutralize each other, forming water and a<br />

salt:<br />

HA + XOH ---> H2O + XA<br />

Keeping in mind that the acid, the base and the salt all ionize, we can write this:<br />

Finally, we can drop all spectator ions, to get this:<br />

H + + A¯ + X + + OH¯ ---> H2O + X + + A¯<br />

H + + OH¯ ---> H2O<br />

These ideas covered all of the known acids at the time (the usual suspects like hydrochloric acid,<br />

acetic acid, and so on) and most of the bases (sodium hydroxide, potassium hydroxide, calcium<br />

hydroxide and so on). HOWEVER, and it is a big however, the theory did not explain why ammonia<br />

(NH3) was a base. There are other problems with the theory also.<br />

III. Problems with Arrhenius' Theory<br />

1. The solvent has no role to play in Arrhenius' theory. An acid is expected to be an acid in any<br />

solvent. This was found to not be the case. For example, HCl is an acid in water, behaving in<br />

the manner Arrhenius expected. However, if HCl is dissolved in benzene, there is no<br />

dissociation, the HCl remaining as un-dissociated molecules. The nature of the solvent plays a<br />

critical role in acid-base properties of substances.<br />

2. All salts in Arrhenius' theory should produce solutions that are neither acidic or basic. This is<br />

not the case. If equal amounts of HCl and ammonia react, the solution is slightly acidic. If equal<br />

amounts of acetic acid and sodium hydroxide are reacted, the resulting solution is basic.<br />

Arrhenius had no explanation for this.<br />

3. The need for hydroxide as the base led Arrhenius to propose the formula NH4OH as the<br />

formula for ammonia in water. This led to the misconception that NH4OH is the actual base,<br />

not NH3.<br />

In fact, by 1896, several years before Arrhenius announced his theory, it had been recognized that<br />

characteristic base properties where just as evident in such solvents as aniline, where no hydroxide<br />

ions were possible.<br />

4. H + , a bare proton, does not exist for very long in water. The proton affinity of H2O is about 799<br />

kJ/mol. Consequently, this reaction:<br />

H2O + H + ---> H3O +<br />

happens to a very great degree. The "concentration" of free protons in water has been estimated to<br />

be 10¯130 M. A rather preposterous value, indeed.<br />

The Arrhenius theory of acids and bases will be fully supplanted by the theory proposed<br />

independently by Johannes and Thomas Lowry in 1923.


The acid base theory of Brønsted and Lowry<br />

I. Introduction<br />

In 1923, within several months of each other, Johannes Nicolaus Brønsted (Denmark) and Thomas<br />

Martin Lowry (England) published essentially the same theory about how acids and bases behave.<br />

Since they came to their conclusions independently of each other, both names have been used for<br />

the theory name.<br />

II. The Acid Base Theory<br />

Using the words of Brønsted:<br />

". . . acids and bases are substances that are capable of splitting off or taking up hydrogen ions,<br />

respectively."<br />

Or an acid-base reaction consists of the transfer of a proton from an acid to a base. KEEP THIS<br />

THOUGHT IN MIND!!<br />

Here is a more recent way to say the same thing:<br />

An acid is a substance from which a proton can be removed.<br />

A base is a substance that can remove a proton from an acid.<br />

Remember: proton, hydrogen ion and H + all mean the same thing<br />

Very common in the chemistry world is this definition set:<br />

An acid is a "proton donor."<br />

A base is a "proton acceptor."<br />

In an acid, the hydrogen ion is bonded to the rest of the molecule. It takes energy (sometimes a little,<br />

sometimes a lot) to break that bond. So the acid molecule does not "give" or "donate" the proton, it<br />

has it taken away. In the same sense, you do not donate your wallet to the pickpocket, you have it<br />

removed from you.<br />

The base is a molecule with a built-in "drive" to collect protons. As soon as the base approaches the<br />

acid, it will (if it is strong enough) rip the proton off the acid molecule and add it to itself.<br />

Now this is where all the fun stuff comes in that you get to learn. You see, some bases are stronger<br />

than others, meaning some have a large "desire" for protons, while other bases have a weaker drive.<br />

It's the same way with acids, some have very weak bonds and the proton is easy to pick off, while<br />

other acids have stronger bonds, making it harder to "get the proton."<br />

One important contribution coming from Lowry has to do with the state of the hydrogen ion in solution.<br />

In Brønsted's announcement of the theory, he used H + . Lowry, in his paper (actually a long letter to<br />

the editor) used the H3O + that is commonly used today.<br />

III. Sample Equations written in the Brønsted-Lowry Style<br />

A. Reactions that proceed to a large extent:<br />

153


HCl + H2O ⇌ H3O + + Cl¯<br />

HCl - this is an acid, because it has a proton available to be transferred.<br />

H2O - this is a base, since it gets the proton that the acid lost.<br />

Now, here comes an interesting idea:<br />

H3O + - this is an acid, because it can give a proton.<br />

Cl¯ - this is a base, since it has the capacity to receive a proton.<br />

Notice that each pair (HCl and Cl¯ as well as H2O and H3O + differ by one proton (symbol = H + ). These<br />

pairs are called conjugate pairs.<br />

HNO3 + H2O ⇌ H3O + + NO3¯<br />

The acids are HNO3 and H3O + and the bases are H2O and NO3¯.<br />

Remember that an acid-base reaction is a competition between two bases (think about it!) for a<br />

proton. If the stronger of the two acids and the stronger of the two bases are reactants (appear on the<br />

left side of the equation), the reaction is said to proceed to a large extent.<br />

Here are some more conjugate acid-base pairs to look for:<br />

H2O and OH¯<br />

HCO3¯ and CO3 2¯<br />

H2PO4¯ and HPO4 2¯<br />

HSO4¯ and SO4 2¯<br />

NH4 + and NH3<br />

CH3NH3 + and CH3NH2<br />

HC2H3O2 and C2H3O2¯<br />

B. Reactions that proceed to a small extent:<br />

If the weaker of the two acids and the weaker of the two bases are reactants (appear on the left side<br />

of the equation), the reaction is said to proceed to only a small extent:<br />

HC2H3O2 + H2O ⇌ H3O + + C2H3O2¯<br />

NH3 + H2O ⇌ NH4 + + OH¯<br />

Identify the conjugate acid base pairs in each reaction.<br />

HC 2H 3O 2 and C 2H 3O 2¯<br />

is one conjugate pair.<br />

H 2O and H 3O + is the other.<br />

NH 3 and NH 4<br />

+<br />

is one pair.<br />

H 2O and OH¯ is the other.<br />

Notice that H 2O in the first equation is acting as a base and in the second equation is acting as an acid.<br />

154


IV. Problems with the Theory<br />

This theory works very nicely in all protic solvents (water, ammonia, acetic acid, etc.), but fails to<br />

explain acid base behavior in aprotic solvents such as benzene and dioxane. That job will be left for a<br />

more general theory, such as the Lewis Theory of Acids and Bases.<br />

The Lewis theory of acids and bases<br />

I. Introduction<br />

Lewis gives his definition of an acid and a base:<br />

"We are inclined to think of substances as possessing acid or basic properties, without having a<br />

particular solvent in mind. It seems to me that with complete generality we may say that a basic<br />

substance is one which has a lone pair of electrons which may be used to complete the stable group<br />

of another atom, and that an acid is one which can employ a lone pair from another molecule in<br />

completing the stable group of one of its own atoms."<br />

"In other words, the basic substance furnishes a pair of electrons for a chemical bond, the acid<br />

substance accepts such a pair."<br />

It is important to make two points here:<br />

1. NO hydrogen ion need be involved.<br />

2. NO solvent need be involved.<br />

The Lewis theory of acids and bases is more general than the "one sided" nature of the Bronsted-<br />

Lowry theory. Keep in mind that Bronsted-Lowry, which defines an acid as a proton donor and a base<br />

as a proton acceptor, REQUIRES the presence of a solvent, specifically a protic solvent, of which<br />

water is the usual example. Since almost all chemistry is done in water, the fact that this limits the<br />

Bronsted-Lowry definition is of little practical consequence.<br />

The Lewis definitions of acid and base do not have the constraints that the Bronsted-Lowry theory<br />

does and, as we shall see, many more reactions were seen to be acid base in nature using the Lewis<br />

definition than when using the Bronsted-Lowry definitions.<br />

II. The Acid Base Theory<br />

The modern way to define a Lewis acid and base is a bit more concise than above:<br />

Acid: an electron acceptor.<br />

Base: an electron donor.<br />

A "Lewis acid" is any atom, ion, or molecule which can accept electrons and a "Lewis base" is any<br />

atom, ion, or molecule capable of donating electrons. However, a warning: many textbooks will say<br />

"electron pair" where I have only written "electron." The truth is that it sometimes is an electron pair<br />

and sometimes it is not.<br />

It turns out that it may be more accurate to say that "Lewis acids" are substances which are electrondeficient<br />

(or low electron density) and "Lewis bases" are substances which are electron-rich (or high<br />

electron density).<br />

155


Several categories of substances can be considered Lewis acids:<br />

1. positive ions<br />

2. having less than a full octet in the valence shell<br />

3. polar double bonds (one end)<br />

4. expandable valence shells<br />

Several categories of substances can be considered Lewis bases:<br />

1. negative ions<br />

2. one of more unshared pairs in the valence shell<br />

3. polar double bonds (the other end)<br />

4. the presence of a double bond<br />

Sören Sörenson and the pH scale<br />

I. Short Historical Introduction<br />

In the late 1880's, Svante Arrhenius proposed that acids were substances that delivered hydrogen ion<br />

to the solution. He has also pointed out that the law of mass action could be applied to ionic<br />

reactions, such as an acid dissociating into hydrogen ion and a negatively charged anion.<br />

This idea was followed up by Wilhelm Ostwald, who calculated the dissociation constants (the<br />

modern symbol is Ka) of many weak acids. Ostwald also showed that the size of the constant is a<br />

measure of an acid's strength.<br />

By 1894, the dissociation constant of water (today called Kw) was measured to the modern value of<br />

1 x 10¯14 .<br />

In 1904, H. Friedenthal recommended that the hydrogen ion concentration be used to characterize<br />

solutions. He also pointed out that alkaline (modern word = basic) solutions could also be<br />

characterized this way since the hydroxyl concentration was always 1 x 10¯14 ÷ the hydrogen ion<br />

concentration. Many consider this to be the real introduction of the pH scale.<br />

III. The Introduction of pH<br />

Sörenson defined pH as the negative logarithm of the hydrogen ion concentration.<br />

pH = - log [H + ]<br />

Remember that sometimes H3O + is written, so<br />

pH = - log [H3O + ]<br />

means the same thing.<br />

So let's try a simple problem: The [H + ] in a solution is measured to be 0.010 M. What is the pH?<br />

The solution is pretty straightforward. Plug the [H + ] into the pH definition:<br />

pH = - log 0.010<br />

An alternate way to write this is:<br />

pH = - log 10¯2<br />

Since the log of 10¯2 is -2, we have:<br />

pH = - (- 2)<br />

Which, of course, is 2.<br />

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Let's discuss significant figures and pH.<br />

Another sample problem: Calculate the pH of a solution in which the [H3O + ] is 1.20 x 10¯3 M.<br />

For the solution, we have:<br />

pH = - log 1.20 x 10¯3<br />

This problem can be done very easily using your calculator. However, be warned about putting<br />

numbers into the calculator.<br />

So you enter (-), log, 1.20, X10 n , (-), 3, enter.<br />

The answer, to the proper number of significant digits is: 2.921.<br />

III. Significant Figures in pH<br />

Here is the example problem: Calculate the pH of a solution where the [H + ] is 0.00100 M. (This could<br />

also be a pOH problem. The point being made is the same.)<br />

OK, you say, that's pretty easy, the answer is 3. After all, 0.00100 is 10¯3 and the negative log of 10¯3<br />

is 3.<br />

You would be graded wrong!! Why? Because the pH is not written to reflect the number of significant<br />

figures in the concentration.<br />

Notice that there are three sig figs in 0.00100. (Hopefully you remember significant figures, since you<br />

probably studied them months ago before getting to acid base stuff. THEY ARE STILL IMPORTANT!)<br />

So, our pH value should also reflect three significant figures.<br />

However, there is a special rule to remember with pH (and pOH) values. The whole number portion<br />

DOES NOT COUNT when figuring out how many digits to write down.<br />

Let's phrase that another way: in a pH (and a pOH), the only place where significant figures are<br />

contained is in the decimal portion.<br />

So, the correct answer to the above problem is 3.000. Three sig figs and they are all in the decimal<br />

portion, NOT (I repeat NOT) in the whole number portion.<br />

Practice Problems<br />

Convert each hydrogen ion concentration into a pH. Identify each as an acidic pH or a basic pH.<br />

1. 0.0015<br />

2. 5.0 x 10¯9<br />

3. 1.0<br />

4. 3.27 x 10¯4<br />

5. 1.00 x 10¯12<br />

6. 0.00010<br />

2.82 acidic pH<br />

8.30 basic pH<br />

0.00 acidic pH<br />

3.485 acidic pH<br />

12.000 basic pH<br />

4.00 acidic pH<br />

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1. 2.82<br />

2. 8.30<br />

3. 0.00<br />

4. 3.485<br />

5. 12.000<br />

6. 4.00<br />

Sörenson also just mentions the reverse direction. That is, suppose you know the pH and you want to<br />

get to the hydrogen ion concentration ([H + ])?<br />

Here is the equation for that:<br />

[H + ] = 10¯pH<br />

That's right, ten to the minus pH gets you back to the [H + ] (called the hydrogen ion concentration).<br />

This is actually pretty easy to do with the calculator. Here's the sample problem: calculate the [H + ]<br />

from a pH of 2.45.<br />

This problem can be done very easily using your calculator. However, be warned about putting<br />

numbers into the calculator.<br />

So you enter 2nd, 10 x , (-), 2.45, enter.<br />

The answer, to the proper number of significant digits is: .00355.<br />

The pH of an acidic pond is 5. What is the hydrogen ion concentration (moles per liter)?<br />

The answer is:<br />

pH = -log (hydrogen ion concentration)<br />

The answer was .00001. Thus, 5 = -log (.00001).<br />

We'll take the formula that you started with (pH = -log([H+])) and work to the answer (solve for [H+]).<br />

pH = - log ([H+]) Given.<br />

pH = log ([H+] (-1) ) Since logarithms are like exponents, when you multiply a log by<br />

something, you can just move it to the inside of log as an exponent.<br />

10 pH = 10 log ([H+] (-1)) Take each side to tenth power.<br />

10 pH = [H+] (-1) Since "log" is just another notation for "log base 10", when you<br />

raise a log to the tenth power, the log cancels out.<br />

[H+] = 10 (-pH)<br />

Take the reciprocal of both sides.<br />

That is the general form. To answer the specific question,<br />

5 = - log ([H+])<br />

5 = log ([H+] (-1) )<br />

10 5 = [H+] (-1)<br />

10 (-5) = [H+]<br />

[H+]<br />

= .00001 mol/L<br />

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On your calculator you would input 10, ^, (-), 5 and you would get 0.00001.<br />

This is also the way to find the amount of OH + that are present in a base.<br />

To find the pH: -log(concentration)<br />

To find the concentration: 10 -pH<br />

Define these terms:<br />

pH scale<br />

The pH scale measures how acidic or basic a substance is. The pH scale ranges from 0<br />

to 14.<br />

Hydronium ion<br />

The hydrogen ion bonded to a molecule of water, H 3 O + , the form in which hydrogen ions<br />

are found in aqueous solution.<br />

Arrhenius acid/base<br />

As defined by Arrhenius, acid-base reactions are characterized by acids, which dissociate in<br />

aqueous solution to form hydrogen ions and bases, which form hydroxide ions. Acids are<br />

defined as a compound or element that releases hydrogen ions into the solution.<br />

Lewis acid/base<br />

In the Lewis theory of acid-base reactions, bases donate pairs of electrons and acids<br />

accept pairs of electrons. A Lewis acid is therefore any substance, such as the H + ion,<br />

that can accept a pair of nonbonding electrons.<br />

Bronsted-Lowry acid/base<br />

In this theory, acids are defined as proton donors; whereas bases are defined as proton<br />

acceptors.<br />

Strong acid/base<br />

Acids and bases that are completely ionized when dissolved in water are called strong<br />

acids and strong bases<br />

Weak acid/base<br />

Weak acids and bases are only partially ionized in their solutions<br />

Neutralization reaction<br />

A neutralization reaction is when an acid and a base react to form water and a salt and<br />

involves the combination of H+ ions and OH- ions to generate water. The neutralization<br />

of a strong acid and strong base has a pH equal to 7.<br />

Titration<br />

Titration is the slow addition of one solution of a known concentration to a known<br />

volume of another solution of unknown concentration until the reaction reaches<br />

neutralization, which is often indicated by a color change.<br />

159


The Learning Goal for this assignment is:<br />

The student will learn what happens during oxidation and<br />

reduction and how to balance redox equations.<br />

1. Oxidation Numbers<br />

Redox Reactions<br />

Oxidation and reduction<br />

Every atom, ion or polyatomic ion has a formal oxidation number associated with it. This value<br />

compares the number of protons in an atom (positive charge) and the number of electrons assigned<br />

to that atom (negative charge).<br />

In many cases, the oxidation number reflects the actual charge on the atom, but there are many<br />

cases where it does not. Think of oxidation numbers as a bookkeeping exercise simply to keep track<br />

of where electrons go.<br />

2. Reduction<br />

Reduction means what it says: the oxidation number is reduced in reduction.<br />

This is accomplished by adding electrons. The electrons, being negative, reduce the overall oxidation<br />

number of the atom receiving the electrons.<br />

3. Oxidation<br />

Oxidation is the reverse process: the oxidation number of an atom is increased during oxidation.<br />

This is done by removing electrons. The electrons, being negative, make the atom that lost them<br />

more positive.<br />

I use this mnemonic to help me remember which is which: LEO the lion says GER.<br />

LEO = Loss of Electrons is Oxidation<br />

GER = Gain of Electrons is Reduction<br />

Another well-known mnemonic is this: OIL RIG<br />

OIL = Oxidation Is Loss (of Electrons)<br />

RIG = Reduction Is Gain (of Electrons)<br />

Another way is to simply remember that reduction is to reduce the oxidation number. Therefore,<br />

oxidation must increase the value.<br />

4. Reduction-Oxidation Reactions<br />

There are many chemical reactions in which one substance gets reduced in oxidation number<br />

(reduction) while another participating substance gets increased in oxidation number (oxidation).<br />

Such a reaction is called called a REDOX reaction. The RED, of course, comes from REDuction and<br />

OX from OXidation. However, it is pronounced re-dox and not red-ox.<br />

Here is a simple example of a redox reaction:<br />

160


Ag+ + Cu ---> Ag + Cu2+<br />

I have deliberately not balanced it and I have also written it in net ionic form. I have found that kids<br />

studying redox get confused by net ionic form and how to change a full equation into net ionic form.<br />

Redox equations need to be balanced but, except for the simplest ones, it cannot be done by<br />

inspection (also called trial and error). I take that back, complex ones can be done by trial and error. It<br />

typically takes quite a bit of work, especially when compared to how long it takes when the proper<br />

technique is used.<br />

There is a technique used to balance redox reactions. It is called "balancing by half-reactions." The<br />

basic plan will be to split the full equation into two simpler parts (called half-reactions), balance them<br />

following several standard steps, then recombine the balanced half-reactions into the final answer.<br />

This is another technique called the "ion-electron method." I plan to ignore it.<br />

Notes:<br />

Redox equations need to be balanced out. There is a technique used to balance redox<br />

reactions<br />

5. Some Definitions<br />

Oxidizing Agent - that substance which oxidizes somebody else. It is reduced in the process.<br />

Reducing Agent - that substance which reduces somebody else. It is oxidized in the process.<br />

It helps me to remember these definitions by the opposite nature of what happens. By that, I mean<br />

the oxidizing agent gets reduced and the reducing agent gets oxidized.<br />

6. Rules for Assigning Oxidation Numbers<br />

The Oxidation Number of an element corresponds to the number of electrons, e - , that an atom loses,<br />

gains, or appears to use when joining with other atoms in compounds. In determining the Oxidation<br />

Number of an atom, there are seven guidelines to follow:<br />

1. The Oxidation Number of an individual atom is 0. This includes diatomic elements such as<br />

O2 or others like P4 and S8<br />

2. The total Oxidation Number of all atoms in: a neutral species is 0 and in an ion is equal to the<br />

ion charge.<br />

3. Group 1 metals have an Oxidation Number of +1 and Group 2 an Oxidation Number of +2<br />

4. The Oxidation Number of fluorine is -1 in compounds<br />

5. Hydrogen generally has an Oxidation Number of +1 in compounds, except hydrides<br />

6. Oxygen generally has an Oxidation Number of -2 in compounds, except peroxides<br />

7. In binary metal compounds, Group 17 elements have an Oxidation Number of -1, Group 16 of -<br />

2, and Group 15 of -3.<br />

Note: The sum of the Oxidation Number s is equal to zero for neutral compounds and equal to the<br />

charge for polyatomic ion species.<br />

Now, some examples:<br />

1. What is the oxidation number of Cl in HCl?<br />

Since H = +1, the Cl must be -1 (minus one).<br />

161


2. What is the oxidation number of Na in Na2O?<br />

Since O = -2, the two Na must each be +1.<br />

3. What is the oxidation number of Cl in ClO¯?<br />

The O is -2, but since a -1 must be left over, then the Cl is +1.<br />

4. What is the oxidation number for each element in KMnO4?<br />

K = +1 because KCl exists. We know the Cl = -1 because HCl exists.<br />

O = -2 by definition<br />

Mn = +7. There are 4 oxygens for a total of -8, K is +1, so Mn must be the rest.<br />

5. What is the oxidation number of S in SO4 2¯<br />

O = -2. There are four oxygens for -8 total. Since -2 must be left over, the S must = +6.<br />

Please note that, if there is no charge indicated on a formula, the total charge is taken to be zero.<br />

Practice Problems<br />

Find oxidation numbers<br />

1. N in NO3¯<br />

2. C in CO3 2¯<br />

+5<br />

+4<br />

3. Cr in CrO4 2¯<br />

+6<br />

4. Cr in Cr2O7 2¯ +6<br />

5. Fe in Fe2O3<br />

6. Pb in PbOH +<br />

+3<br />

+2<br />

7. V in VO2 +<br />

8. V in VO 2+<br />

+5<br />

+4<br />

9. Mn in MnO4¯<br />

+7<br />

10. Mn in MnO4 2¯<br />

Notes:<br />

+6<br />

Then you have a - at the end you subtract the other oxidation number<br />

When you have a positive you add more to the other oxidation<br />

number<br />

162


7. Half Reactions<br />

A half-reaction is simply one which shows either reduction OR oxidation, but not both. Here is the<br />

example redox reaction used in a different file:<br />

Ag + + Cu → Ag + Cu 2+<br />

It has BOTH a reduction and an oxidation in it. That is why we call it a redox reaction, from REDuction<br />

and OXidation.<br />

What you must be able to do is look at a redox reaction and separate out the two half-reactions in it.<br />

To do that, identify the atoms which get reduced and get oxidized. Here are the two half-reactions<br />

from the above example:<br />

Ag+ → Ag<br />

Cu → Cu 2+<br />

The silver is being reduced, its oxidation number going from +1 to zero. The copper's oxidation<br />

number went from zero to +2, so it was oxidized in the reaction. In order to figure out the halfreactions,<br />

you MUST be able to calculate the oxidation number of an atom.<br />

Keep in mind that a half-reaction shows only one of the two behaviors we are studying. A single halfreaction<br />

will show ONLY reduction or ONLY oxidation, never both in the same equation.<br />

Also, notice that the reaction is read from left to right to determine if it is reduction or oxidation. If you<br />

read the reaction in the opposite direction (from right to left) it then becomes the other of our two<br />

choices (reduction or oxidation). For example, the silver half-reaction above is a reduction, but in the<br />

reverse direction it is an oxidation, going from zero on the right to +1 on the left.<br />

There will be times when you want to switch a half-reaction from one of the two types to the other. In<br />

that case, rewrite the entire equation and swap sides for everything involved. If I needed the silver<br />

half-reaction to be oxidation, I'd write Ag → Ag+ rather than just doing it mentally.<br />

The next step is that both half-reactions must be balanced. However, there is a twist. When you<br />

learned about balancing equation, you made equal the number of atoms of each element on each<br />

side of the arrow. That still applies, but there is one more thing: the total amount of charge on each<br />

side of the half-reaction MUST be the same.<br />

When you look at the two half-reactions above, you will see they are already balanced for atoms with<br />

one Ag on each side and one Cu on each side. So, all we need to do is balance the charge. To do<br />

this you add electrons to the more positive side. You add enough to make the total charge on each<br />

side become EQUAL.<br />

To the silver half-reaction, we add one electron:<br />

To the copper half-reaction, we add two electrons:<br />

Ag+ + e¯ ---> Ag<br />

Cu ---> Cu 2+ + 2e¯<br />

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One point of concern: notice that each half-reaction wound up with a total charge of zero on each<br />

side. This is not always the case. You need to strive to get the total charge on each side EQUAL, not<br />

zero.<br />

One more point to make before wrapping this up. A half-reaction is a "fake" chemical reaction. It's just<br />

a bookkeeping exercise. Half-reactions NEVER occur alone. If a reduction half-reaction is actually<br />

happening (say in a beaker in front of you), then an oxidation reaction is also occurring. The two halfreactions<br />

can be in separate containers, but they do have to have some type of "chemical<br />

connection" between them.<br />

Half-Reaction Practice Problems<br />

Balance each half-reaction for atoms and charge:<br />

1) Cl2 → Cl¯<br />

2) Sn → Sn 2+<br />

3) Fe 2+ → Fe 3+<br />

4) I3¯ → I¯<br />

5) ICl2¯ → I¯ (I'm being mean on this one. Hint: the iodine is the only thing reduced or oxidized.)<br />

ICl 2¯ + 2e¯ →I¯ + 2Cl¯<br />

Separate each of these redox reactions into their two half-reactions (but do not balance):<br />

6) Sn + NO3¯ →SnO2 + NO2<br />

7) HClO + Co →Cl2 + Co 2+<br />

8) NO2 →NO3¯ + NO<br />

Here are the two half-reactions to be combined:<br />

Here is the rule to follow:<br />

Ag+ + e¯ → Ag<br />

Cu → Cu 2+ + 2e¯<br />

the total electrons MUST cancel when the two half-reactions are added.<br />

Another way to say it:<br />

Cl 2 + 2e¯ →2Cl¯<br />

Sn →Sn 2+ + 2e¯<br />

Fe 2+ →Fe 3+ + e¯<br />

I 3¯ → 3I¯ + 2e¯<br />

Sn →SnO 2 and NO 3¯ →NO 2<br />

HClO →Cl 2 and Co ---> Co 2+<br />

NO 2 →NO 3¯ and NO 2 →NO<br />

the number of electrons in each half-reaction MUST be equal when the two half-reactions are<br />

added.<br />

What that means is that one (or both) equations must be multiplied through by a factor. The value of<br />

the factor is selected so as to make the number of electrons equal.<br />

In our example problem, the top reaction (the one with silver) must be multiplied by two, like this:<br />

164<br />

2Ag+ + 2e¯ → 2Ag


Notice that each separate substance is increased by the factor amount. Occasionally, a student will<br />

multiply ONLY the electrons by the factor. That is incorrect.<br />

When the two half-reactions are added, we get:<br />

2Ag+ + 2e¯ + Cu → 2Ag + Cu 2+ + 2e¯<br />

With two electrons on each side, they may be canceled, resulting in:<br />

2Ag+ + Cu → 2Ag + Cu 2+<br />

This is the correct answer. Notice that there are two silvers on each side and one copper. Notice also<br />

that the total charge on each side is +2. It is balanced for both atoms and charge. Sometimes, I am<br />

asked if the order matters, if the Cu could be first on the left-hand side. The answer is that the order<br />

does not matter. There happen to be certain styles about where particular substances are put in the<br />

final answer, but these are only styles. They do not affect the chemical correctness of the answer.<br />

Notes:<br />

The total number electrons must cancel when the two half-reactions are<br />

added.<br />

Practice Problems<br />

Separate into half-reactions, balance them and then recombine.<br />

1) Sn + Cl2 ---> Sn 2+ + Cl¯<br />

Sn 0 -->Sn 2+ +2e - e - +Cl 0 -->Cl 1- --> Sn 2+ +2Cl -<br />

2) Fe 2+ + I3¯ ---> Fe 3+ + I¯<br />

???????????????????????????????<br />

1. N in NO 3¯<br />

The O is -2 and three of them makes -6. Since -1 is left over, the N must be +5<br />

2. C in CO 3<br />

2¯<br />

The O is -2 and three of them makes -6. Since -2 is left over, the C must be +4<br />

3. Cr in CrO 4<br />

2¯<br />

The O is -2 and four of them makes -8. Since -2 is left over, the Cr must be +6<br />

4. Cr in Cr 2 O 7<br />

2¯<br />

The O is -2 and seven of them makes -14. Since -2 is left over, the two Cr must be +12<br />

What follows is an important point. Each Cr is +6. Each one. We do not speak of Cr 2 being +12. Each Cr atom is considered individually.<br />

5. Fe in Fe 2 O 3<br />

The O is -2 and three of them makes -6. Each Fe must then be +3<br />

6. +2 9. +7<br />

7. +5 10. +6<br />

8. +4<br />

1) Cl 2 + 2e¯ →2Cl¯ 5) ICl 2¯<br />

+ 2e¯ →I¯ + 2Cl¯<br />

2) Sn →Sn 2+ + 2e¯ 6) Sn →SnO 2 and NO 3¯<br />

→NO 2<br />

3) Fe 2+ →Fe 3+ + e¯ 7) HClO →Cl 2 and Co ---> Co 2+<br />

4) I 3¯ → 3I¯ + 2e¯ 8) NO 2 →NO 3¯<br />

and NO 2 →NO<br />

Note that in this last redox equation the NO 2 (actually just the N) is both being reduced AND being oxidized. In the first half-reaction, the N goes from +4<br />

to +5 (oxidation) and in the second, the N goes from +4 to +2 (reduction).<br />

By the way, we could flip the reaction so that NO 3¯<br />

and NO are reacting together to produce only one product, the NO 2 . In that case, the two halfreactions<br />

would be reversed.<br />

165


Reference Tables for Physical Setting/CHEMISTRY<br />

Table A<br />

Standard Temperature and Pressure<br />

Name Value Unit<br />

Standard Pressure 101.3 kPa kilopascal<br />

1 atm atmosphere<br />

Standard Temperature 273 K kelvin<br />

0°C degree Celsius<br />

Table D<br />

Selected Units<br />

Symbol Name Quantity<br />

m meter length<br />

g gram mass<br />

Pa pascal pressure<br />

K kelvin temperature<br />

Table B<br />

Physical Constants for Water<br />

mol<br />

J<br />

mole<br />

joule<br />

amount of<br />

substance<br />

energy, work,<br />

quantity of heat<br />

Heat of Fusion<br />

Heat of Vaporization<br />

Specific Heat Capacity of H 2<br />

O()<br />

Specific Heat Capacity of H 2<br />

O(s)<br />

Specific Heat Capacity of H 2<br />

O(g)<br />

Table C<br />

Selected Prefixes<br />

Factor Prefix Symbol<br />

10 3 kilo- k<br />

334 J/g<br />

2260 J/g<br />

4.18 J/g•K<br />

2.10 J/g•K<br />

2.01 J/g•K<br />

s second time<br />

min minute time<br />

h hour time<br />

d day time<br />

y year time<br />

L liter volume<br />

ppm parts per million concentration<br />

M<br />

molarity<br />

solution<br />

concentration<br />

u atomic mass unit atomic mass<br />

10 –1 deci- d<br />

10 –2 centi- c<br />

10 –3 milli- m<br />

10 –6 micro- μ<br />

10 –9 nano- n<br />

10 –12 pico- p<br />

R1


Table E<br />

Selected Polyatomic Ions<br />

Formula Name Formula Name<br />

H 3<br />

O +<br />

hydronium<br />

CrO 4<br />

2–<br />

chromate<br />

Hg 2<br />

2+<br />

mercury(I)<br />

Cr 2<br />

O 7<br />

2–<br />

dichromate<br />

NH 4<br />

+<br />

C 2<br />

H 3<br />

O<br />

–<br />

2 –}<br />

CH 3<br />

COO<br />

CN –<br />

CO 3<br />

2–<br />

HCO<br />

–<br />

3<br />

C 2<br />

O<br />

2–<br />

4<br />

ClO –<br />

ammonium<br />

acetate<br />

cyanide<br />

carbonate<br />

hydrogen<br />

carbonate<br />

oxalate<br />

hypochlorite<br />

MnO 4<br />

–<br />

NO<br />

–<br />

2<br />

NO<br />

–<br />

3<br />

O<br />

2–<br />

2<br />

OH –<br />

PO 4<br />

3–<br />

SCN –<br />

SO 3<br />

2–<br />

permanganate<br />

nitrite<br />

nitrate<br />

peroxide<br />

hydroxide<br />

phosphate<br />

thiocyanate<br />

sulfite<br />

ClO 2<br />

–<br />

chlorite<br />

SO 4<br />

2–<br />

sulfate<br />

ClO 3<br />

–<br />

chlorate<br />

HSO 4<br />

–<br />

hydrogen sulfate<br />

ClO 4<br />

–<br />

perchlorate<br />

S 2<br />

O 3<br />

2–<br />

thiosulfate<br />

Table F<br />

Solubility Guidelines for Aqueous Solutions<br />

Ions That Form<br />

Soluble Compounds<br />

Group 1 ions<br />

(Li + , Na + , etc.)<br />

ammonium (NH 4 + )<br />

nitrate (NO 3 – )<br />

acetate (C 2<br />

H 3<br />

O 2 – or<br />

CH 3<br />

COO – )<br />

hydrogen carbonate<br />

(HCO 3 – )<br />

chlorate (ClO 3 – )<br />

halides (Cl – , Br – , I – )<br />

Exceptions<br />

when combined with<br />

Ag + , Pb 2+ , or Hg 2<br />

2+<br />

sulfates (SO 4 2– ) when combined with Ag + ,<br />

Ca 2+ , Sr 2+ , Ba 2+ , or Pb 2+<br />

Ions That Form<br />

Insoluble Compounds*<br />

Exceptions<br />

carbonate (CO 3 2– ) when combined with Group 1<br />

ions or ammonium (NH 4 + )<br />

chromate (CrO 4 2– ) when combined with Group 1<br />

ions, Ca 2+ , Mg 2+ , or<br />

ammonium (NH 4 + )<br />

phosphate (PO 4 3– ) when combined with Group 1<br />

ions or ammonium (NH 4 + )<br />

sulfide (S 2– ) when combined with Group 1<br />

ions or ammonium (NH 4 + )<br />

hydroxide (OH – ) when combined with Group 1<br />

ions, Ca 2+ , Ba 2+ , Sr 2+ , or<br />

ammonium (NH 4 + )<br />

*compounds having very low solubility in H 2 O<br />

R2


150.<br />

140.<br />

Table G<br />

Solubility Curves at Standard Pressure<br />

KI<br />

NaNO 3<br />

130.<br />

120.<br />

KNO 3<br />

110.<br />

100.<br />

Solubility (g solute/100. g H 2<br />

O)<br />

90.<br />

80.<br />

70.<br />

60.<br />

HCl<br />

NH 4<br />

Cl<br />

KCl<br />

50.<br />

40.<br />

30.<br />

NaCl<br />

KClO 3<br />

NH 3<br />

20.<br />

10.<br />

SO 2<br />

0<br />

0 10. 20. 30. 40. 50. 60. 70. 80. 90. 100.<br />

Temperature (°C)<br />

R3


Table H<br />

Vapor Pressure of Four Liquids<br />

200.<br />

propanone<br />

ethanol<br />

150.<br />

water<br />

Vapor Pressure (kPa)<br />

100.<br />

101.3 kPa<br />

ethanoic<br />

acid<br />

50.<br />

0<br />

0 25 50. 75 100. 125<br />

R4


Table I<br />

Heats of Reaction at 101.3 kPa and 298 K<br />

Reaction<br />

ΔH (kJ)*<br />

CH 4<br />

(g) + 2O 2<br />

(g) CO 2<br />

(g) + 2H 2<br />

O() –890.4<br />

C 3<br />

H 8<br />

(g) + 5O 2<br />

(g) 3CO 2<br />

(g) + 4H 2<br />

O() –2219.2<br />

2C 8<br />

H 18<br />

() + 25O 2<br />

(g) 16CO 2<br />

(g) + 18H 2<br />

O() –10943<br />

2CH 3<br />

OH() + 3O 2<br />

(g) 2CO 2<br />

(g) + 4H 2<br />

O() –1452<br />

C 2<br />

H 5<br />

OH() + 3O 2<br />

(g) 2CO 2<br />

(g) + 3H 2<br />

O() –1367<br />

C 6<br />

H 12<br />

O 6<br />

(s) + 6O 2<br />

(g) 6CO 2<br />

(g) + 6H 2<br />

O() –2804<br />

2CO(g) + O 2<br />

(g) 2CO 2<br />

(g) –566.0<br />

C(s) + O 2<br />

(g) CO 2<br />

(g) –393.5<br />

4Al(s) + 3O 2<br />

(g) 2Al 2<br />

O 3<br />

(s) –3351<br />

N 2<br />

(g) + O 2<br />

(g) 2NO(g) +182.6<br />

N 2<br />

(g) + 2O 2<br />

(g) 2NO 2<br />

(g) +66.4<br />

2H 2<br />

(g) + O 2<br />

(g) 2H 2<br />

O(g) –483.6<br />

2H 2<br />

(g) + O 2<br />

(g) 2H 2<br />

O() –571.6<br />

N 2<br />

(g) + 3H 2<br />

(g) 2NH 3<br />

(g) –91.8<br />

2C(s) + 3H 2<br />

(g) C 2<br />

H 6<br />

(g) –84.0<br />

2C(s) + 2H 2<br />

(g) C 2<br />

H 4<br />

(g) +52.4<br />

2C(s) + H 2<br />

(g) C 2<br />

H 2<br />

(g) +227.4<br />

H 2<br />

(g) + I 2<br />

(g) 2HI(g) +53.0<br />

KNO 3<br />

(s) H 2 O K + (aq) + NO 3 – (aq) +34.89<br />

NaOH(s) H 2 O Na + (aq) + OH – (aq) –44.51<br />

NH 4<br />

Cl(s) H 2 O NH 4 + (aq) + Cl – (aq) +14.78<br />

NH 4<br />

NO 3<br />

(s) H 2 O NH 4 + (aq) + NO 3 – (aq) +25.69<br />

NaCl(s) H 2 O Na + (aq) + Cl – (aq) +3.88<br />

LiBr(s) H 2 O Li + (aq) + Br – (aq) –48.83<br />

H + (aq) + OH – (aq) H 2<br />

O() –55.8<br />

*The ΔH values are based on molar quantities represented in the equations.<br />

A minus sign indicates an exothermic reaction.<br />

Most<br />

Active<br />

Least<br />

Active<br />

Table J<br />

Activity Series**<br />

Metals Nonmetals Most<br />

Active<br />

Li<br />

Rb<br />

K<br />

Cs<br />

Ba<br />

Sr<br />

Ca<br />

Na<br />

Mg<br />

Al<br />

Ti<br />

Mn<br />

Zn<br />

Cr<br />

Fe<br />

Co<br />

Ni<br />

Sn<br />

Pb<br />

H 2<br />

Cu<br />

Ag<br />

Au<br />

F 2<br />

Cl 2<br />

Br 2<br />

I 2<br />

**Activity Series is based on the hydrogen<br />

standard. H 2 is not a metal.<br />

Least<br />

Active<br />

R5


Table K<br />

Common Acids<br />

Table N<br />

Selected Radioisotopes<br />

HCl(aq)<br />

Formula<br />

HNO 2<br />

(aq)<br />

HNO 3<br />

(aq)<br />

H 2<br />

SO 3<br />

(aq)<br />

H 2<br />

SO 4<br />

(aq)<br />

H 3<br />

PO 4<br />

(aq)<br />

H 2<br />

CO 3<br />

(aq)<br />

or<br />

CO 2<br />

(aq)<br />

CH 3<br />

COOH(aq)<br />

or<br />

HC 2<br />

H 3<br />

O 2<br />

(aq)<br />

Name<br />

hydrochloric acid<br />

nitrous acid<br />

nitric acid<br />

sulfurous acid<br />

sulfuric acid<br />

phosphoric acid<br />

carbonic acid<br />

ethanoic acid<br />

(acetic acid)<br />

Nuclide Half-Life Decay<br />

Mode<br />

Nuclide<br />

Name<br />

198 Au 2.695 d β – gold-198<br />

14 C 5715 y β – carbon-14<br />

37 Ca 182 ms β + calcium-37<br />

60 Co 5.271 y β – cobalt-60<br />

137 Cs 30.2 y β – cesium-137<br />

53 Fe 8.51 min β + iron-53<br />

220 Fr 27.4 s α francium-220<br />

3 H 12.31 y β – hydrogen-3<br />

131 I 8.021 d β – iodine-131<br />

37 K 1.23 s β + potassium-37<br />

42 K 12.36 h β – potassium-42<br />

Table L<br />

Common Bases<br />

85 Kr 10.73 y β – krypton-85<br />

16 N 7.13 s β – nitrogen-16<br />

Formula<br />

NaOH(aq)<br />

KOH(aq)<br />

Ca(OH) 2<br />

(aq)<br />

NH 3<br />

(aq)<br />

Name<br />

sodium hydroxide<br />

potassium hydroxide<br />

calcium hydroxide<br />

aqueous ammonia<br />

19 Ne 17.22 s β + neon-19<br />

32 P 14.28 d β – phosphorus-32<br />

239 Pu 2.410 × 10 4 y α plutonium-239<br />

226 Ra 1599 y α radium-226<br />

222 Rn 3.823 d α radon-222<br />

90 Sr 29.1 y β – strontium-90<br />

Table M<br />

Common Acid–Base Indicators<br />

Approximate<br />

Indicator pH Range Color<br />

for Color Change<br />

Change<br />

methyl orange 3.1–4.4 red to yellow<br />

bromthymol blue 6.0–7.6 yellow to blue<br />

phenolphthalein 8–9 colorless to pink<br />

litmus 4.5–8.3 red to blue<br />

bromcresol green 3.8–5.4 yellow to blue<br />

thymol blue 8.0–9.6 yellow to blue<br />

99 Tc 2.13 × 10 5 y β – technetium-99<br />

232 Th 1.40 × 10 10 y α thorium-232<br />

233 U 1.592 × 10 5 y α uranium-233<br />

235 U 7.04 × 10 8 y α uranium-235<br />

238 U 4.47 × 10 9 y α uranium-238<br />

Source: CRC Handbook of Chemistry and Physics, 91 st ed., 2010–2011,<br />

CRC Press<br />

Source: The Merck Index, 14 th ed., 2006, Merck Publishing Group<br />

R6


Table O<br />

Symbols Used in Nuclear Chemistry<br />

Name Notation Symbol<br />

alpha particle<br />

4<br />

2<br />

He or 4 2 α α<br />

beta particle<br />

0<br />

–1<br />

e or 0<br />

–1 β β–<br />

gamma radiation<br />

0<br />

0<br />

γ γ<br />

neutron<br />

1<br />

0<br />

n n<br />

proton<br />

1<br />

1<br />

H or 1 1 p p<br />

positron<br />

0<br />

+1<br />

e or 0<br />

+1 β β+<br />

Table P<br />

Organic Prefixes<br />

Prefix<br />

meth- 1<br />

eth- 2<br />

prop- 3<br />

but- 4<br />

pent- 5<br />

hex- 6<br />

hept- 7<br />

oct- 8<br />

non- 9<br />

dec- 10<br />

Number of<br />

Carbon Atoms<br />

Table Q<br />

Homologous Series of Hydrocarbons<br />

Name General Examples<br />

Formula Name Structural Formula<br />

R7<br />

alkanes C n<br />

H 2n+2<br />

ethane<br />

alkenes C n<br />

H 2n<br />

ethene<br />

alkynes C n<br />

H 2n–2<br />

ethyne<br />

Note: n = number of carbon atoms<br />

H H<br />

H C C H<br />

H H<br />

H<br />

H<br />

C C<br />

H<br />

H<br />

H C C H


Table R<br />

Organic Functional Groups<br />

Class of<br />

Compound<br />

Functional<br />

Group<br />

General<br />

Formula<br />

Example<br />

halide<br />

(halocarbon)<br />

F (fluoro-)<br />

Cl (chloro-)<br />

Br (bromo-)<br />

I (iodo-)<br />

R X<br />

(X represents<br />

any halogen)<br />

CH 3<br />

CHClCH 3<br />

2-chloropropane<br />

alcohol<br />

OH<br />

R<br />

OH<br />

CH 3<br />

CH 2<br />

CH 2<br />

OH<br />

1-propanol<br />

ether<br />

O<br />

R O R′<br />

CH 3<br />

OCH 2<br />

CH 3<br />

methyl ethyl ether<br />

aldehyde<br />

O<br />

C H<br />

R<br />

O<br />

C H<br />

O<br />

CH 3<br />

CH 2<br />

C H<br />

propanal<br />

ketone<br />

O<br />

C<br />

O<br />

R C R′<br />

O<br />

CH 3<br />

CCH 2<br />

CH 2<br />

CH 3<br />

2-pentanone<br />

organic acid<br />

O<br />

C OH<br />

R<br />

O<br />

C OH<br />

O<br />

CH 3<br />

CH 2<br />

C OH<br />

propanoic acid<br />

ester<br />

O<br />

C O<br />

O<br />

R C O R′<br />

O<br />

CH 3<br />

CH 2<br />

COCH 3<br />

methyl propanoate<br />

amine<br />

N<br />

R<br />

R′<br />

N R′′<br />

CH 3<br />

CH 2<br />

CH 2<br />

NH 2<br />

1-propanamine<br />

amide<br />

O<br />

C NH<br />

R<br />

O R′<br />

C NH<br />

O<br />

CH 3<br />

CH 2<br />

C NH 2<br />

propanamide<br />

Note: R represents a bonded atom or group of atoms.<br />

R8


0<br />

6.941<br />

+1<br />

Li<br />

3<br />

2-1<br />

Na<br />

39.0983<br />

K +1<br />

19<br />

2-8-8-1<br />

85.4678 +1<br />

Rb<br />

Cs<br />

(223)<br />

Fr<br />

87<br />

-18-32-18-8-1<br />

+1<br />

Ra<br />

88<br />

-18-32-18-8-2<br />

39<br />

138.9055<br />

La<br />

57<br />

2-8-18-18-9-2<br />

+2 (227)<br />

Ac<br />

89<br />

-18-32-18-9-2<br />

47.867<br />

Ti<br />

22<br />

2-8-10-2<br />

91.224<br />

Zr<br />

40<br />

2-8-18-10-2<br />

+3 178.49<br />

Hf<br />

72<br />

*18-32-10-2<br />

+3 (261)<br />

Rf<br />

104<br />

+2<br />

+3<br />

+4<br />

+4<br />

+4<br />

50.9415<br />

V<br />

23<br />

2-8-11-2<br />

+2<br />

+3<br />

+4<br />

+5<br />

51.996<br />

Cr<br />

24<br />

2-8-13-1<br />

95.94<br />

Mo<br />

42<br />

2-8-18-13-1<br />

183.84<br />

W<br />

74<br />

-18-32-12-2<br />

+2<br />

+3<br />

+6<br />

+6<br />

+6<br />

54.9380<br />

Mn<br />

25<br />

2-8-13-2<br />

+2<br />

+3<br />

+4<br />

+7<br />

55.845<br />

Fe<br />

26<br />

2-8-14-2<br />

+2<br />

+3 58.9332<br />

Co<br />

27<br />

2-8-15-2<br />

+2<br />

+3<br />

58.693<br />

Ni<br />

28<br />

2-8-16-2<br />

+2<br />

+3 63.546 Cu<br />

2-8-18-1<br />

107.868<br />

Ag<br />

47<br />

2-8-18-18-1<br />

79<br />

+1<br />

+2<br />

+1<br />

65.409<br />

Zn<br />

30<br />

2-8-18-2<br />

10.81<br />

+3 12.011<br />

B<br />

5<br />

2-3<br />

26.98154<br />

Al<br />

13<br />

2-8-3<br />

+2 69.723<br />

Ga<br />

31<br />

2-8-18-3<br />

+3<br />

+3<br />

–4<br />

+2<br />

+4<br />

C<br />

6<br />

2-4<br />

28.0855<br />

Si<br />

14<br />

2-8-4<br />

72.64<br />

Ge<br />

32<br />

2-8-18-4<br />

Pb<br />

–4<br />

+2<br />

+4<br />

+2<br />

+4<br />

74.9216<br />

As<br />

33<br />

2-8-18-5<br />

Sb<br />

–3<br />

+3<br />

15.9994 O<br />

–2 18.9984<br />

8<br />

2-6 2-7<br />

78.96<br />

Se<br />

34<br />

2-8-18-6<br />

127.60<br />

Te<br />

52<br />

2-8-18-18-6<br />

(209)<br />

Po<br />

84<br />

-18-32-18-6<br />

–2<br />

+4<br />

+6<br />

–2<br />

+4<br />

+6<br />

+2<br />

+4<br />

F<br />

79.904<br />

Br<br />

35<br />

2-8-18-7<br />

126.904<br />

l<br />

53<br />

2-8-18-18-7<br />

(210)<br />

At<br />

85<br />

-18-32-18-7<br />

( ? )<br />

Uus<br />

117<br />

4.00260 0<br />

He<br />

2<br />

2<br />

–1 20.180<br />

Ne<br />

10<br />

2-8<br />

0<br />

22.98977<br />

11<br />

2-8-1<br />

1<br />

1.00794 +1<br />

–1<br />

H<br />

1<br />

1<br />

1<br />

37<br />

2-8-18-8-1<br />

–1<br />

+1<br />

+5<br />

–1<br />

+1<br />

+5<br />

+7<br />

83.798<br />

Kr<br />

36<br />

2-8-18-8<br />

131.29<br />

Xe<br />

54<br />

2-8-18-18-8<br />

(222)<br />

Rn<br />

86<br />

-18-32-18-8<br />

0<br />

+2<br />

0<br />

+2<br />

+4<br />

+6<br />

0<br />

132.905<br />

55<br />

2-8-18-18-8-1<br />

Symbol<br />

Relative atomic masses are based<br />

Group on 12 C = 12 (exact)<br />

Group<br />

2<br />

13 14 15 16 17 18<br />

Atomic Number<br />

+1<br />

+1<br />

9.01218 +2<br />

Be<br />

4<br />

2-2<br />

24.305<br />

Mg<br />

12<br />

2-8-2<br />

40.08<br />

Ca<br />

20<br />

2-8-8-2<br />

87.62<br />

Sr<br />

38<br />

2-8-18-8-2<br />

137.33<br />

Ba<br />

56<br />

2-8-18-18-8-2<br />

(226)<br />

+2<br />

+2<br />

+2<br />

+2<br />

3<br />

44.9559<br />

Sc<br />

21<br />

2-8-9-2<br />

88.9059<br />

Y<br />

2-8-18-9-2<br />

+3<br />

+3<br />

4<br />

KEY<br />

92.9064<br />

Nb +3<br />

+5<br />

41<br />

2-8-18-12-1<br />

180.948<br />

Ta<br />

73<br />

-18-32-11-2<br />

(262)<br />

105<br />

5<br />

Periodic Table of the Elements<br />

Atomic Mass<br />

Electron Configuration<br />

+4<br />

Db<br />

+5<br />

6<br />

(266)<br />

Sg<br />

106<br />

12.011 2-4<br />

–4<br />

6<br />

C<br />

+2<br />

+4<br />

(98)<br />

Tc<br />

43<br />

2-8-18-13-2<br />

186.207<br />

Re<br />

75<br />

-18-32-13-2<br />

(272)<br />

Bh<br />

107<br />

7<br />

Group<br />

+4<br />

+6<br />

+7<br />

+4<br />

+6<br />

+7<br />

8<br />

101.07<br />

Ru<br />

44<br />

2-8-18-15-1<br />

190.23<br />

Os<br />

76<br />

-18-32-14-2<br />

(277)<br />

Hs<br />

108<br />

+3<br />

+3<br />

+4<br />

Selected Oxidation States<br />

Note: Numbers in parentheses<br />

are mass numbers of the most<br />

stable or common isotope.<br />

9<br />

102.906<br />

Rh<br />

45<br />

2-8-18-16-1<br />

192.217<br />

Ir<br />

77<br />

-18-32-15-2<br />

(276)<br />

Mt<br />

109<br />

+3<br />

+3<br />

+4<br />

106.42<br />

Pd<br />

46<br />

2-8-18-18<br />

195.08<br />

Pt<br />

78<br />

-18-32-17-1<br />

+2<br />

+4<br />

+2<br />

+4<br />

196.967<br />

Au<br />

-18-32-18-1<br />

(281)<br />

Ds (280) Rg<br />

110<br />

10<br />

29<br />

111<br />

11 12<br />

+1<br />

+3<br />

112.41<br />

Cd<br />

48<br />

2-8-18-18-2<br />

200.59<br />

Hg<br />

80<br />

-18-32-18-2<br />

(285)<br />

Cn<br />

112<br />

+2 114.818<br />

In<br />

+1<br />

+2<br />

49<br />

2-8-18-18-3<br />

204.383<br />

Tl<br />

81<br />

-18-32-18-3<br />

(284)<br />

Uut<br />

113**<br />

+3<br />

+1<br />

+3<br />

118.71<br />

Sn<br />

50<br />

2-8-18-18-4<br />

207.2<br />

82<br />

-18-32-18-4<br />

(289)<br />

Uuq<br />

114<br />

+2<br />

+4<br />

+2<br />

+4<br />

14.0067 –3<br />

–2<br />

N<br />

–1<br />

7<br />

2-5<br />

30.97376<br />

P<br />

15<br />

2-8-5<br />

121.760<br />

51<br />

2-8-18-18-5<br />

208.980<br />

Bi<br />

83<br />

-18-32-18-5<br />

(288)<br />

Uup<br />

115<br />

+1<br />

+2<br />

+3<br />

+4<br />

+5<br />

–3<br />

+3<br />

+5<br />

+5<br />

–3<br />

+3<br />

+5<br />

+3<br />

+5<br />

32.065<br />

S<br />

16<br />

2-8-6<br />

(292)<br />

Uuh<br />

116<br />

–2<br />

+4<br />

+6<br />

35.453<br />

Cl<br />

17<br />

2-8-7<br />

–1<br />

+1<br />

+5<br />

+7<br />

39.948<br />

Ar<br />

18<br />

2-8-8<br />

18<br />

(294)<br />

Uuo<br />

118<br />

140.116<br />

Ce<br />

58<br />

232.038<br />

Th<br />

90<br />

+3<br />

+4<br />

140.908<br />

Pr +3<br />

59<br />

144.24<br />

Nd<br />

60<br />

+4 231.036<br />

Pa +4 238.029 +5<br />

U +3<br />

+4<br />

+5<br />

+6<br />

91<br />

92<br />

+3<br />

(145)<br />

Pm<br />

61<br />

+3<br />

150.36<br />

Sm<br />

62<br />

+2<br />

+3<br />

151.964<br />

Eu<br />

63<br />

+2<br />

+3<br />

157.25<br />

Gd<br />

64<br />

+3<br />

158.925<br />

(237)Np (244) Pu (243) Am (247) Cm +3 (247) Bk +3<br />

+3<br />

+4<br />

+5<br />

+6<br />

93 94<br />

+3<br />

+4<br />

+5<br />

+6<br />

65<br />

+3<br />

+4<br />

+5<br />

+6<br />

95 96 97<br />

Tb<br />

+3<br />

+4<br />

162.500<br />

Dy<br />

66<br />

(251)<br />

+3<br />

164.930<br />

Ho<br />

67<br />

+3<br />

167.259<br />

Er<br />

68<br />

Cf +3 (252) Es (257) Fm<br />

100<br />

98 99<br />

+3<br />

+3<br />

+3<br />

168.934<br />

Tm +3<br />

69<br />

(258)<br />

Md<br />

101<br />

+2<br />

+3<br />

173.04<br />

Yb<br />

70<br />

(259)<br />

No<br />

102<br />

+2<br />

+3<br />

+2<br />

+3<br />

174.9668<br />

Lu<br />

71<br />

(262)<br />

Lr<br />

103<br />

+3<br />

+3<br />

*denotes the presence of (2-8-) for elements 72 and above<br />

**The systematic names and symbols for elements of atomic numbers 113 and above<br />

will be used until the approval of trivial names by IUPAC.<br />

Source: CRC Handbook of Chemistry and Physics, 91 st ed., 2010–2011, CRC Press<br />

9<br />

R9<br />

Period<br />

1<br />

2<br />

3<br />

4<br />

5<br />

6<br />

7


Table S<br />

Properties of Selected Elements<br />

First<br />

Atomic Symbol Name Ionization<br />

Electro- Melting Boiling* Density** Atomic<br />

Number Energy negativity Point Point (g/cm 3 ) Radius<br />

(kJ/mol) (K) (K) (pm)<br />

1 H hydrogen 1312 2.2 14 20. 0.000082 32<br />

2 He helium 2372 — — 4 0.000164 37<br />

3 Li lithium 520. 1.0 454 1615 0.534 130.<br />

4 Be beryllium 900. 1.6 1560. 2744 1.85 99<br />

5 B boron 801 2.0 2348 4273 2.34 84<br />

6 C carbon 1086 2.6 — — .— 75<br />

7 N nitrogen 1402 3.0 63 77 0.001145 71<br />

8 O oxygen 1314 3.4 54 90. 0.001308 64<br />

9 F fluorine 1681 4.0 53 85 0.001553 60.<br />

10 Ne neon 2081 — 24 27 0.000825 62<br />

11 Na sodium 496 0.9 371 1156 0.97 160.<br />

12 Mg magnesium 738 1.3 923 1363 1.74 140.<br />

13 Al aluminum 578 1.6 933 2792 2.70 124<br />

14 Si silicon 787 1.9 1687 3538 2.3296 114<br />

15 P phosphorus (white) 1012 2.2 317 554 1.823 109<br />

16 S sulfur (monoclinic) 1000. 2.6 388 718 2.00 104<br />

17 Cl chlorine 1251 3.2 172 239 0.002898 100.<br />

18 Ar argon 1521 — 84 87 0.001633 101<br />

19 K potassium 419 0.8 337 1032 0.89 200.<br />

20 Ca calcium 590. 1.0 1115 1757 1.54 174<br />

21 Sc scandium 633 1.4 1814 3109 2.99 159<br />

22 Ti titanium 659 1.5 1941 3560. 4.506 148<br />

23 V vanadium 651 1.6 2183 3680. 6.0 144<br />

24 Cr chromium 653 1.7 2180. 2944 7.15 130.<br />

25 Mn manganese 717 1.6 1519 2334 7.3 129<br />

26 Fe iron 762 1.8 1811 3134 7.87 124<br />

27 Co cobalt 760. 1.9 1768 3200. 8.86 118<br />

28 Ni nickel 737 1.9 1728 3186 8.90 117<br />

29 Cu copper 745 1.9 1358 2835 8.96 122<br />

30 Zn zinc 906 1.7 693 1180. 7.134 120.<br />

31 Ga gallium 579 1.8 303 2477 5.91 123<br />

32 Ge germanium 762 2.0 1211 3106 5.3234 120.<br />

33 As arsenic (gray) 944 2.2 1090. — 5.75 120.<br />

34 Se selenium (gray) 941 2.6 494 958 4.809 118<br />

35 Br bromine 1140. 3.0 266 332 3.1028 117<br />

36 Kr krypton 1351 — 116 120. 0.003425 116<br />

37 Rb rubidium 403 0.8 312 961 1.53 215<br />

38 Sr strontium 549 1.0 1050. 1655 2.64 190.<br />

39 Y yttrium 600. 1.2 1795 3618 4.47 176<br />

40 Zr zirconium 640. 1.3 2128 4682 6.52 164<br />

R10


First<br />

Atomic Symbol Name Ionization<br />

Electro- Melting Boiling* Density** Atomic<br />

Number Energy negativity Point Point (g/cm 3 ) Radius<br />

(kJ/mol) (K) (K) (pm)<br />

41 Nb niobium 652 1.6 2750. 5017 8.57 156<br />

42 Mo molybdenum 684 2.2 2896 4912 10.2 146<br />

43 Tc technetium 702 2.1 2430. 4538 11 138<br />

44 Ru ruthenium 710. 2.2 2606 4423 12.1 136<br />

45 Rh rhodium 720. 2.3 2237 3968 12.4 134<br />

46 Pd palladium 804 2.2 1828 3236 12.0 130.<br />

47 Ag silver 731 1.9 1235 2435 10.5 136<br />

48 Cd cadmium 868 1.7 594 1040. 8.69 140.<br />

49 In indium 558 1.8 430. 2345 7.31 142<br />

50 Sn tin (white) 709 2.0 505 2875 7.287 140.<br />

51 Sb antimony (gray) 831 2.1 904 1860. 6.68 140.<br />

52 Te tellurium 869 2.1 723 1261 6.232 137<br />

53 I iodine 1008 2.7 387 457 4.933 136<br />

54 Xe xenon 1170. 2.6 161 165 0.005366 136<br />

55 Cs cesium 376 0.8 302 944 1.873 238<br />

56 Ba barium 503 0.9 1000. 2170. 3.62 206<br />

57 La lanthanum 538 1.1 1193 3737 6.15 194<br />

Elements 58–71 have been omitted.<br />

72 Hf hafnium 659 1.3 2506 4876 13.3 164<br />

73 Ta tantalum 728 1.5 3290. 5731 16.4 158<br />

74 W tungsten 759 1.7 3695 5828 19.3 150.<br />

75 Re rhenium 756 1.9 3458 5869 20.8 141<br />

76 Os osmium 814 2.2 3306 5285 22.587 136<br />

77 Ir iridium 865 2.2 2719 4701 22.562 132<br />

78 Pt platinum 864 2.2 2041 4098 21.5 130.<br />

79 Au gold 890. 2.4 1337 3129 19.3 130.<br />

80 Hg mercury 1007 1.9 234 630. 13.5336 132<br />

81 Tl thallium 589 1.8 577 1746 11.8 144<br />

82 Pb lead 716 1.8 600. 2022 11.3 145<br />

83 Bi bismuth 703 1.9 544 1837 9.79 150.<br />

84 Po polonium 812 2.0 527 1235 9.20 142<br />

85 At astatine — 2.2 575 — — 148<br />

86 Rn radon 1037 — 202 211 0.009074 146<br />

87 Fr francium 393 0.7 300. — — 242<br />

88 Ra radium 509 0.9 969 — 5 211<br />

89 Ac actinium 499 1.1 1323 3471 10. 201<br />

Elements 90 and above have been omitted.<br />

*boiling point at standard pressure<br />

**density of solids and liquids at room temperature and density of gases at 298 K and 101.3 kPa<br />

— no data available<br />

Source: CRC Handbook for Chemistry and Physics, 91 st ed., 2010–2011, CRC Press<br />

R11


Table T<br />

Important Formulas and Equations<br />

d = density<br />

m<br />

Density d = m = mass<br />

V<br />

V = volume<br />

Mole Calculations number of moles =<br />

given mass<br />

gram-formula mass<br />

measured value – accepted value<br />

Percent Error % error = × 100<br />

accepted value<br />

mass of part<br />

Percent Composition % composition by mass = × 100<br />

mass of whole<br />

mass of solute<br />

parts per million = × 1000000<br />

mass of solution<br />

Concentration<br />

molarity =<br />

moles of solute<br />

liter of solution<br />

Combined Gas Law<br />

P<br />

P = pressure<br />

1<br />

V 1<br />

P<br />

= 2<br />

V 2<br />

V = volume<br />

T 1<br />

T 2 T = temperature<br />

M A<br />

= molarity of H + M B<br />

= molarity of OH –<br />

Titration M A<br />

V A<br />

= M B<br />

V B<br />

V A<br />

= volume of acid V B<br />

= volume of base<br />

q = mCΔT q = heat H f<br />

= heat of fusion<br />

Heat q = mH f<br />

m = mass H v<br />

= heat of vaporization<br />

q = mH v<br />

C=specific heat capacity<br />

ΔT = change in temperature<br />

Temperature<br />

K = °C + 273<br />

K = kelvin<br />

°C = degree Celsius<br />

R12


Collier County CHEMISTRY EXAM FORMULA AND RESOURCE PACKET<br />

GENERAL<br />

D m V<br />

[ ExperimentalValue AcceptedVa lue]<br />

% error <br />

x100<br />

AcceptedVa lue<br />

% yield <br />

ExperimentalYield<br />

TheoreticalYield<br />

x100<br />

CONCENTRATIONS<br />

moles of solute<br />

M = Molarity <br />

liters of solution<br />

KEY<br />

P = pressure<br />

V = volume<br />

T = temperature<br />

n = number of moles<br />

m = mass<br />

M = molar mass (grams/mole)<br />

D = density<br />

KE = kinetic energy<br />

Avogadro’s Number = 6.02 x 10 23<br />

GASES, LIQUIDS, SOLUTIONS<br />

m = Molality <br />

M1V1 M2V2<br />

S1<br />

P1<br />

S 2<br />

P 2<br />

ACID/BASE<br />

pH = - log[H + ]<br />

[H + ]=10 -pH<br />

moles of solute<br />

kilograms of solvent<br />

<br />

Gas constant<br />

R 8.314 L kPa L atm L mmHg<br />

0.0821 62.4<br />

K mol K mol K mol<br />

1 atm = 760 mmHg = 760 torr = 101.3 kPa<br />

K = o C + 273<br />

o C = K - 273<br />

STP = Standard Temperature and Pressure = 0 o C<br />

and 1 atm<br />

P V<br />

1 1<br />

<br />

P2V<br />

2<br />

pOH = - log [OH - ]<br />

[OH - ]= 10 -pOH<br />

pH + pOH = 14<br />

Kw = [H + ] x [OH - ] = 1.0 x 10 -14 M 2<br />

V<br />

T<br />

1<br />

1<br />

P<br />

T<br />

1<br />

1<br />

V<br />

<br />

T<br />

P<br />

<br />

T<br />

2<br />

2<br />

2<br />

2<br />

Or V1T2 = V2T1<br />

Or P1T2 = P2T1<br />

THERMOCHEMISTRY<br />

ΔH= mCΔT, where ΔT = T f - T<br />

P1V<br />

1<br />

T<br />

1<br />

<br />

P2V<br />

2<br />

T<br />

2<br />

Or<br />

P1V1T2=P2V2T1<br />

q = mCΔT<br />

PV<br />

nRT<br />

Specific Heat of Water = 4.18 J/g*˚C or 1.0 cal/g*˚C<br />

Specific Heat of Ice = 2.1 J/g*˚C or 0.5 cal/g*˚C<br />

Specific Heat of Steam = 2.0 J/g*˚C or 0.4 cal/g*˚C<br />

P<br />

Total<br />

P<br />

1<br />

P<br />

2<br />

Rate A<br />

Rate B<br />

...<br />

<br />

Molar MassB<br />

Molar MassA<br />

R13


CHEMISTRY EXAM FORMULA AND RESOURCE PACKET<br />

Solubility of Compounds at 25 o C and 1 atm<br />

acetate<br />

bromide<br />

carbonate<br />

chlorate<br />

chloride<br />

hydroxide<br />

iodide<br />

nitrate<br />

oxide<br />

perchlorate<br />

phosphate<br />

sulfate<br />

sulfide<br />

aluminum S S - S S I S S I S I S d<br />

ammonium S S S S S S S S - S S S S<br />

barium S S I S S S S S sS S I I d<br />

calcium S S I S S S S S sS S I sS I<br />

copper(II) S S - S S I S S I S I S I<br />

iron(II) S S I S S I S S I S I S I<br />

iron(III) S S - S S I S S I S I sS d<br />

lithium S S sS S S S S S S S sS S S<br />

magnesium S S I S S I S S I S I S d<br />

potassium S S S S S S S S S S S S S<br />

silver sS I I S I - I S I S I sS I<br />

sodium S S S S S S S S S S S S S<br />

strontium S S I S S S S S S S I I I<br />

zinc S S I S S I S S I S I S I<br />

S=soluble<br />

sS = slightly soluble in water<br />

I = insoluble in water<br />

d = decomposes in water<br />

- = no such compound<br />

R14


CHEMISTRY EXAM FORMULA AND RESOURCE PACKET<br />

Common Polyatomic Ions<br />

1- Charge 2- Charge 3- Charge<br />

Formula Name Formula Name Formula Name<br />

H₂PO₄<br />

Dihydrogen<br />

Hydrogen<br />

HPO₄<br />

Phosphate<br />

phosphate PO₃ Phosphite<br />

C₂H₃O₂ Acetate C₂O₄ Oxalate PO₄ Phosphate<br />

HSO₃ Hydrogen<br />

sulfite<br />

SO₃ Sulfite<br />

HSO₄<br />

HCO₃<br />

Hydrogen<br />

SO₄<br />

sulfate<br />

Sulfate<br />

Hydrogen<br />

carbonate<br />

CO₃<br />

Carbonate<br />

NO₂ Nitrite CrO₄ Chromate 1+ Charge<br />

NO₃ Nitrate Cr₂O₇ Dichromate Formula Name<br />

CN Cyanide SiO₃ Silicate NH₄ Ammonium<br />

OH<br />

MnO₄<br />

ClO<br />

Hydroxide<br />

Permanganate<br />

Hypochlorite<br />

S₂O₃ Thiosulfate H₃O Hydronium<br />

ClO₂ Chlorite<br />

ClO₃<br />

Chlorate<br />

ClO₄ Perchlorate<br />

R15


Activity Series of Metals<br />

Name<br />

Symbol<br />

D<br />

Lithium<br />

Li<br />

e<br />

Potassium<br />

K<br />

c<br />

r<br />

Barium<br />

Ba<br />

e<br />

Calcium<br />

Ca<br />

a<br />

Sodium<br />

Na<br />

s<br />

i<br />

Magnesium<br />

Mg<br />

n<br />

Aluminum<br />

Al<br />

g<br />

Zinc<br />

Zn<br />

Iron<br />

Fe<br />

A<br />

c<br />

Nickel<br />

Ni<br />

t<br />

Tin<br />

Sn<br />

i<br />

v<br />

Lead<br />

Pb<br />

i<br />

(Hydrogen)<br />

(H)*<br />

t<br />

Copper<br />

Cu<br />

y<br />

Mercury<br />

Hg<br />

Silver<br />

Ag<br />

Gold<br />

Au<br />

*Metals from Li to Na will replace H from acids and water; from Mg to<br />

Pb they will replace H from acids only.<br />

Decreasing<br />

Activity<br />

Activity Series of Nonmetal (Halogens)<br />

Name<br />

Symbol<br />

Fluorine F 2<br />

Chlorine Cl 2<br />

Bromine Br 2<br />

Iodine I 2<br />

R16

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