Chapter 12 Homework

12.1 Liquids

1. Describe the liquid state according to the kinetic molecular theory.

2. List the properties of liquids.

3. How does the kinetic molecular theory explain the following properties of liquids:
a) their relatively high density;
b) their ability to diffuse; and
c) their ability to evaporate.

4. Explain why liquids in a test tube form a meniscus.

5. Compare vaporization and evaporation.

6. Define fluid.

7. Define surface tension.

12.2 Solids

1. Describe the solid state according to the kinetic molecular theory.

2. What is the difference between an amorphous solid and a crystalline solid?

3. Account for each of the following properties of solids:
a) the definite volume;
b) the relatively high density of solids;
c) the extremely low rate of diffusion

4. Compare and contrast the four types of crystals.

5. a) List the four common examples of amorphous solids;
b) Why is glass sometimes classified as a supercooled liquid?
c) Name some uses of glass.

6. Distinguish between a crystal structure, a lattice and a unit cell.

12.3 Change of State

1. Define equilibrium.

2. State LeChatelier’s principle.

3. a) What happens when a liquid vapor system at equilibrium experiences an increase in temperature?
b) What happens when it experiences a decrease in temperature?

4. What would be an example of deposition?

5. Define the equilibrium vapor pressure of a liquid.

6. Define boiling point of a liquid.

7. In the phase diagram for water, what is meant by the
a) triple point;
b) critical point

8. Refer to the phase diagram for water on page 381 to answer the following questions:
a) Describe all the phase changes a sample of solid water would undergo when heated to its critical temperature at a pressure of 1.00 atm;
b) Describe all the phase changes a sample of water vapor would undergo when cooled to 50 C at a pressure of 1.00 atm;
c) At approximately what pressure will water be a vapor at 00 C?
d) Within what range of pressures will water be a liquid at temperatures above its normal boiling point?

9. Using Figure 12-12, estimate the approximate equilibrium vapor pressure of each of the following at the specified temperature:
a) water at 400 C;
b) water at 800 C;
c) diethyl ether at 200 C;
d) ethanol at 600 C.

10. Give two examples of substances that sublime at ordinary temperatures.

11. Explain why the vapor pressure of a liquid increases with increasing temperature.

12. a) Explain the relationship between atmospheric pressure and the actual boiling point of a liquid;
b) During continual boiling at this pressure (the pressure at which the liquid boils), what is the relationship between the temperature of the liquid and that of its vapor;
c) How can this phenomenon be explained.

13. Explain the relationship between the magnitude of the molar heat of vaporization of a liquid and the strength of attraction between the particles of that liquid.

12.4 Water

1. Why is a water molecule polar?

2. How is the structure of water responsible for some of water’s unique characteristics?

3. Describe the arrangement of molecules in liquid water and in ice.

4. a) Why does ice float?
b) Why is this phenomenon important?

5. What quantity of heat energy is released when 506 g of liquid water freezes?

6. What mass of steam is required to release 4.97 kJ of heat energy on condensation?