Skyler Wild - Final Chemistry Notebook

The Learning Goal for this assignment is: The Students will learn how the interactions
between water molecules account for the unique properties of water and how aqueous
solutions form.
Take note over the following chapter. Use the Headings provided to organize your notes. Define and number all highlighted vocabulary (total 22 ) as well
as summarize and take notes over the sections. You may add pictures where needed. The pictures should be an appropriate size. Use Arial 12 for all
text. This document should be 2 pages and should be saved as a pdf before you submit it into Angel.
15.1 Water and Its Properties
Chapter 15 Water and Aqueous Systems
Pages 488 - 507
Water in the Liquid State
Key Question: What factor causes the high surface tension, low vapor pressure, and high boiling point of water?
Water is the basis of life, every living thing needs it, it is apparent in the form of solid, gas, and liquid which is always
present in the atmosphere.
Polar molecules are attracted to one another by diploe interactions, the negative end of one molecule attracts to the
positive end of another, in water that attraction results in hydrogen bonding. Hydrogen bonds are attractive forces that
arise when a hydrogen atom is covalently bonded to a very electronegative atom and also weakly bonded to an unshared
electron pair of another electronegative atom.
Many unique and important properties of water- including its high surface tension, low vapor pressure, and high boiling
point- result from hydrogen bonds.
The inward force, or pull, that tends to minimize the surface area of a liquid is called surface tension.
All liquids have a surface tension, but water’s surface tension is higher than most. It is possible to decrease the surface
tension 1 of water by adding surfactant. A surfactant 2 is any substance that interferes with the hydrogen bonding between
water molecules and thereby reduces surface tension.
The vapor pressure of a liquid is the result of molecules escaping from the surface of the liquid and molecules in liquid
water to one another.
Water has a molar mass of 18.0 g/mol, but it has a boiling point of 100 degrees Celsius, the difference between boiling
points of compounds is due to hydrogen bonding, which is more extensive in water than, as shown in the example,
Ammonia.
Water in the Solid State
Key Question: How can you describe the structure of ice?
Water in the liquid state exhibits some unique properties, the same is true for water in the solid state. Ice cubes float in
your glasses of iced tea because solid water has a lower density than liquid water. Why is ice less dense than water?
Hydrogen bonds hold the water molecules in place in the solid phase.
The structure of ice is a regular open framework of water molecules in a hexagonal arrangement.
When ice melts, the framework collapses.
A layer of ice on top of a body of water acts as an insulator for the water beneath, preventing water from freezing solid
except under extreme conditions.
Ice melts at zero degrees Celsius, which is a high melting temperature for a molecule with such a low molar mass.
15.2 Homogeneous Aqueous Systems
Solutions
Key Question: What types of substances dissolve most readily in water?
An aqueous solution 3 is water that contains dissolves substances.
In a solution, the dissolving medium is the solvent. The particles dissolved in a solution are the solute. A solvent 4 dissolves
the solute 5 , and the solute becomes dispersed in the solvent.
Solutions are homogenous mixtures; they are also stable mixtures.
Substances that dissolve most readily in water include ionic compounds and other polar covalent compounds.
Water molecules are constantly in motion; this is because they have kinetic energy.
The process by which the positive and negative ions of an ionic solid become surrounded by solvent molecules is called
solvation 6 .
In some ionic compounds the attractions among the ions in the crystals are stronger than the attractions exerted by water.
Molecules in oil can easily separate and replace molecules in gasoline to form a solution. As a rule, polar solvents such as
water dissolve ionic compounds and polar compounds.
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