Sample Questions for Final Exam

Spring Final Exam Review Name:________________________
2011 Period:________
Unit 8: Empirical & Molecular Formulas
1. What is the percent by mass of iron in the compound Fe2 O3 ?
a. 70% c. 48%
b. 56% d. 30%
2. What is the molar mass of beryllium oxide (BeO)?
a. 12 g/mol c. 24 g/mol
b. 13 g/mol d. 25 g/mol
3. In the chemical formula for ammonia, NH3, what does the subscript 3 represent?
a. The number of nitrogen and hydrogen c. The number of ammonia molecules that
atoms in each molecule of ammonia
will bond together
b. The number of hydrogen atoms in each d. The number of nitrogen atoms in each
molecule of ammonia
molecule of ammonia
4.
Given the diagram of the molecule, write the empirical and molecular formulas.
a. CH, CH3 c. CH2, CH3
b. CH3, C3H2 d. CH3, C2H6
5. A compound has the following composition: 12.68 % Al 19.72 % N 67.61 % O. Calculate the empirical
formula of this compound
a. Al (NO ) c. Al(NO )
b. Al (NO ) d. Al(NO )
6. “Empirical” means
a. theoretical c. based on data
b. hypothetical d. acquired by armed conflict
7. Nitrogen gas is a diatomic molecule. What is the mass of one mole of nitrogen gas?
a. 7 g c. 28 g
b. 10 g d. 14 g
8. Which of the following is a monatomic gas at STP?
a. chlorine c. helium
b. fluorine d. nitrogen
9. How many moles of CH4 are contained in 96.0 grams of CH4?
a. 6.00 moles c. 5.00 moles
b. 2.00 moles d. 12.0 moles
10. How many molecules are contained in 55.0 g of H2SO4 ?
a. 0.561 c. 3.38X10 23
b. 3.93 d. 2.37X10 24
11. What is the empirical formula of a compound that has a carbon-to-hydrogen ratio of 2 to 6?
a. CH3 c. C3H
b. C2H6 d. C6H2

12. Which formula is both a molecular and an empirical formula?
a. C6H12O6 c. C3H8O
b. C2H4O2 d. C4H8
Unit 9 Ionic and Metallic Bonding
13. The correct chemical formula for iron(II) sulfide is
a. FeS c. FeSO4
b. Fe2S3 d. Fe2(SO4)3
14. Elements from which two groups in the periodic table would most likely combine with each other to form an
ionic compound?
a. 1 and 2 c. 1 and 17
b. 16 and 17 d. 17 and 18
15. A solid substance is an excellent conductor of electricity. The chemical bonds in this substance are most likely
a. ionic, because the valence electrons are shared between atoms
b. ionic, because the valence electrons are mobile
c. metallic, because the valence electrons are stationary
d. metallic, because the valence electrons are mobile
16. The formula for magnesium chloride is
a. MgCl2 c. Mg2Cl3
b. MnCl d. MnCl2
17. Which is a unique characteristic of the bonding between metal atoms?
a. Atoms require additional electrons to reach a stable octet.
b. Atoms must give away electrons to reach a stable octet.
c. Atoms share valence electrons only with neighboring atoms to reach a stable octet.
d. Delocalized electrons move among many atoms creating a sea of electrons.
18. The correct formula of an ionic compound containing Al 3+ and CO3 2- is
a. AlCO3 b. Al(CO3)3 c. Al2(CO3)3 d. Al3(CO3)2
19. When naming a transition metal that has more than one oxidation number, the numeric value of the oxidation
number is indicated by a
a. Roman numeral c. subscript
b. Greek prefix d. suffix
20. Which substance contains bonds that involved the transfer of electrons from one atom to another?
a. CO2 b. NH3 c. KBr d. Cl2
21. Which have the lowest electronegativities?
a. Group 1 metals c. Group 2 metals
b. Group 7 d. transition metals
22. When cations and anions join, they form what kind of chemical bond?
a. ionic b. hydrogen c. metallic d. covalent
23. Cations are formed when neutral atoms lose ---
a. electrons b. protons c. neutrons d. positrons
24. When chlorine gas reacts with sodium metal, what type of substance is formed?
a. a mixture c. an element
b. a compound d. a solution

25. Which two substances cannot be broken down by a chemical change?
a. C and CuO c. CO2 and CuO
b. C and Cu d. CO2 and Cu
26. Which list of formulas represents compounds only?
a. CO2, H2O, NH3 c. H2, Ne, NaCl
b. H2, N2, O2 d. MgO, NaCl, O2
27. An ionic compound is formed when there is a reaction between the elements
a. strontium and chlorine c. nitrogen and oxygen
b. hydrogen and chlorine d. sulfur and oxygen
Chem Unit 10: Covalent Bonding
28. Which pair of elements would most likely bond to form a covalently bonded compound?
a. sodium and fluorine c. phosphorus and oxygen
b. barium and chlorine d. magnesium and sulfur
29. In chemical compounds, covalent bonds form when
a. the electronegativity difference between two atoms is very large
b. electrons are completely transferred between two metals
c. pairs of electrons are shared between two nonmetal atoms
d. two nonmetal ions are attracted to each other by opposite charges
30. Which is the correct formula for dinitrogen pentoxide?
a. N4O b. NO2 c. N2O5 d. NO
31. Which of the following is the name of the molecule PCl3?
a. Phosphorus trichloride c. Potassium trichloride
b. Phosphorus chloride d. Potassium chloride
32. Given a formula for oxygen gas: What is the total number of electrons shared between the atoms represented in
this formula?
a. 1 b. 2 c. 8 d. 4
33. What are shared in covalent bonds?
a. Cations b. Protons c. Electrons d. Anions
34. The formula for dinitrogen tetroxide
a. N2O4 b. N3O3 c. N2O d. NO
35. What is the correct name for the compound P4O6?
a. Phosphoric acid c. Phosphorus(IV) oxide
b. Phosphorus oxide d. Tetraphosphorus hexoxide
36. What is the total number of electrons shared in a double covalent bond between two atoms?
a. 1 b. 2 c. 8 d. 4
37. Which statement describes what occurs as two atoms of bromine combine to become a molecule of bromine?
a. Energy is absorbed as a bond is formed.
b. Energy is absorbed as a bond is broken.
c. Energy is released as a bond is formed.
d. Energy is released as a bond is broken.
Unit 11: Chemical Reactions

38. Some chemical reactions absorb energy, while others release energy. Of the chemical reactions in burning coal
and exploding fireworks, which will release energy?
a. Burning coal only
b. Exploding fireworks only
c. Both burning coal and exploding fireworks
d. Neither burning coal nor exploding fireworks
39. Given the balanced equation representing a reaction: CH4(g) + 2O2(g) 2 H2O(g) + CO2(g) + energy
Which statement is true about energy in this reaction?
a. The reaction is exothermic because it releases energy.
b. The reaction is exothermic because it absorbs energy.
c. The reaction is endothermic because it releases energy.
d. The reaction is endothermic because it absorbs energy.
40. A catalyst lowers the activation energy of a reaction by
a. providing an alternate reaction pathway
b. decreasing the heat of reaction
c. increasing the mass of the reactants
d. changing the mole ratio of the reactants
41. Which statement explains why the speed of some reactions is increased when the surface area of one or all the
reactants is increased?
a. increasing surface area changes the electronegativity of the reactant particles
b. increasing surface area changes the concentration of the reactant particles
c. increasing surface area changes the conductivity of reactant particles
d. increasing surface area enables more reactant particles to collide
42.
The general equation shown is a reaction that is an
a. exothermic decomposition c. endothermic synthesis
b. endothermic decomposition d. exothermic synthesis
43. During all chemical reactions, mass, energy, and charge are
a. absorbed c. formed
b. conserved d. released
44. Consider this reaction: NH3(g) + HCl(g) NH4Cl(s)
Which type of reaction does this equation represent?
a. combustion c. single-replacement
b. decomposition d. synthesis
45.
The type of reaction represented by the above equation is--
a. single replacement c. decomposition
b. double replacement d. synthesis

46. The appropriate model for a decomposition reaction is
47.
a.
b.
What type of reaction does this illustration represent?
a. Decomposition c. Single-replacement
b. Synthesis d. Double-replacement
48. Which of these is the general formula for a double-replacement reaction?
a. A + B AB
b. AB + XY BA + YX
c. AB + XY AY + XB
d. A + B + XY AX + BY
49. ____H2O ____H2 + ____O2
The coefficients for the correctly balanced equation for the reaction illustrated above are...
a. 1, 1, 1 c. 2, 1, 2
b. 1, 1, 2 d. 2, 2, 1
50. A balanced chemical equation has equal numbers of atoms of each type on both sides of the equation. This
illustrates the principle of
a. conservation of energy
b. conservation of mass
c. action and reaction
d. natural selection
51. 4P + 5O2 2P2Ox
The subscript of oxygen in the product should be -
a. 2 c. 10
b. 5 d. 20
52. Which reaction diagram shows the effect of using the appropriate catalyst in a chemical reaction?
a.
c.
d.
c.

.
53. Which term refers to the difference between the potential energy of the products and the potential energy of the
reactants for any chemical change?
a. heat of deposition c. heat of reaction
b. heat of fusion d. heat of vaporization
54. Given the balanced equation representing a reaction: 2HCl(aq) + Na2S2O3(aq) S(s) + H2SO3(aq) + 2NaCl(aq)
Decreasing the concentration of Na2S2O3(aq) decreases the rate of reaction because the
a. activation energy decreases.
b. activation energy increases.
c. frequency of effective collisions decreases.
d. frequency of effective collisions increases.
CHEMISTRY
STOICHIOMETRY
55. Metallic sodium reacts violently with water to form hydrogen and sodium hydroxide according to the balanced
equation: 2Na + 2H2O 2NaOH + H2
How many moles of hydrogen gas are generated when 4.0 moles of sodium react with excess water?
a. 1.0 mole c. 3.0 moles
b. 2.0 moles d. 4.0 moles
56. W+X Y+Z+60 kJ
How many moles of product Z will be formed if 120 kJ of heat was given off in the reaction shown?
a. 2.0 moles c. 3.0 moles
b. 0.50 moles d. 4.0 moles
57. Mg + ZnCl2 MgCl2 + Zn
15 moles of magnesium are reacted with 5 moles of zinc chloride. Which reactant is limiting?
58.
a. Zn c. ZnCl2
b. MgCl2 d. Mg
How many liters of oxygen are required to produce 2 liters of water at STP?
a. 1 c. 3
b. 2 d. 4
d.
59. W+X Y+Z
How many grams of product Z will be formed if 12.0 g of W react with 10.0 g of X to form 8.0 g of product Y in
the reaction shown?
a. 8.0 g c. 12.0 g
b. 10.0 g d. 14.0 g

60.
How many moles of hydrogen gas are produced when 0.066 mole of sodium is completely reacted?
a. 0.022 mol H2 c. 0.066 mol H2
b. 0.033 mol H2 d. 0.099 mol H2
61. Hydrogen chloride can be formed from hydrogen and chlorine as shown in the reaction.
H2 + Cl2 2HCl + heat
Chlorine and fluorine are located in the same group in the periodic table. If the reaction were performed with
fluorine instead of chlorine, how many mole of H2 would be required to balance the equation?
a. 1 c. 4
b. 2 d. 8
Consider the diagram below. In the box below left is a mixture of sulfur dioxide gas and
oxygen gas. The box below right shows the contents after the reaction is complete.
62. Which of the equations below best represents the reaction between sulfur dioxide and oxygen gases?
a. SO2 + O2 SO3
b. 2 SO2 + O2 2 SO3
c. 4 SO2 + 4 O2 4 SO3 + 2 O2
d. SO2 + 2 O2 SO3
63. Which is the limiting reactant?
a. SO2 c. SO3
b. O2 d. none of these is limiting
Acids and Bases
64. Which of the following is an observable property of an acid?
a. They become slippery when reacting with water.
b. They react with metals to release hydrogen gas.
c. They produce salts when mixed with other acids.
d. They become more acidic when mixed with a base.
65. What is the pOH of a solution of KOH with a hydroxide concentration of [OH - ] = 1 x 10 -4 ?
a. -10 c. 4
b. -4 d. 10
66. Potassium hydroxide (KOH) is a strong base because it
a. easily releases hydroxide ions c. does not dissolve in water.
b. reacts to form salt crystals in water. d. does not conduct an electric current.
67. Of four different laboratory solutions, the solution with the highest acidity has a pH of
a. 11 c. 5
b. 7 d. 3

68. Which word equation represents a neutralization reaction?
a. base + acid salt + water
b. base + salt water + acid
c. salt + acid base + water
d. salt + water acid + base
69. A water molecule acts as an acid when the water molecule
a. accepts an H+ c. donates an H+
b. accepts an OH- d. donates an OH-
70. Which of the following is the correct name for the acid identified by the formula HCl?
a. Hydrochloric acid c. Chloric acid
b. Chlorous acid d. Perchloric acid
71. Ulcers are often caused by an excess of stomach acid. Milk of magnesia is often used to soothe the irritation.
Milk of magnesia is probably
a. an acid c. an indicator
b. a base d. a colloid
72. Phenophthalein is an indicator that turns pink when added to a basic solution. In which solution would
phenolphthalein turn pink?
a. NaOH c. H2O
b. HCl d. NaCl
73. In a titration experiment, if 30.0 mL of an HCl solution reacts with 24.6 mL of a 0.50-M NaOH solution, what is
the concentration of the HCl solution?
a. 0.41 M c. 1.5 M
b. 0.61 M d. 370 M
74. What does pH measure?
a. Hydrogen ion concentration c. Acid density
b. Hydroxide ion concentration d. Base density
75. When a base is mixed with an acidic solution, neutralization occurs because the
a. base reaches absolute zero c. base chemically reacts with the acid
b. acid evaporates d. mass of the solution increases
76. Equal volumes of 1 molar hydrochloric acid (HCl) and 1 molar sodium hydroxide base (NaOH) are mixed. After
mixing, the solution will be
a. strongly acidic c. nearly neutral
b. weakly acidic d. weakly basic
77. An aqueous solution of lithium hydroxide contains hydroxide ions as the only negative ion in the solution.
Lithium hydroxide is classified as an
a. aldehyde c. acid
b. alcohol d. base
78. One acid-base theory defines a base as an
a. H+ donor c. H donor
b. H+ acceptor d. H acceptor
79. During which process can 10.0 milliliters of a 0.05 M HCl(aq) solution be used to determine the unknown
concentration of a given volume of NaOH(aq) solution?
a. evaporation c. filtration
b. distillation d. titration

80. A solution having an equal number of H + ions and OH - ions will have a pH of
a. 3 c. 9
b. 7 d. 11
Unit 15: Redox Reactions
81. Consider this chemical reaction: 2AgBr(s) + energy 2Ag(s) + Br2(l)
Which is true about the reaction?
a. Silver is reduced. c. Silver loses electrons.
b. Bromine is reduced. d. Bromine gains electrons.
82. In HNO3, the oxidation state of hydrogen is +1 and the oxidation state of oxygen is -2. Therefore, the oxidation
state of nitrogen is --
a. -1 c. +4
b. +3 d. +5
83. Given the balanced ionic equation representing a reaction: 2Al 3+ (aq) + 3Mg(s) 3Mg 2+ (aq) + 3Al(s)
In this reaction, electrons are transferred from
a. Al to Mg 2+ c. Mg to Al 3+
b. Al 3+ to Mg d. Mg 2+ to Al
84. Which equation represents an oxidation-reduction reaction?
a. Na + Cl2 NaCl
b. H2SO4 + Ca(OH)2 CaSO4 + 2H2O
c. MgCrO4 + BaCl2 MgCl2 + BaCrO4
d. Zn(NO3)2 +Na2CO3 2NaNO3 + ZnCO3
85. Given the balanced equation representing a reaction: 2KClO3(s) 2KCl(s) + 3O2(g)
The oxidation state of chlorine in this reaction changes from
a. -1 to +1 c. +1 to -1
b. -1 to +5 d. +5 to -1