1. The assumption of kinetic theory that explains why the pressure exerted by an enclosed gas is constant is that

a. gases are composed of tiny invisible particles.

b. the particles of a gas are in constant rapid motion

c. molecules of a gas display no attraction or repulsion

d. collision between molecules of a gas are perfectly elastic.

2. The change in phase from a liquid to a gas is

a. condensation

b. sublimation.

c. evaporation.

d. fusion.

3. At the boiling point of a liquid the particles of the liquid have gained enough energy to

a. form bubbles of gas in the liquid itself.

b. move from their fixed position in the liquid.

c. separate into electrons, protons, and neutrons.

d. lose their identity as a particular substance.

4. The normal boiling point of a liquid

a. does not change with location or elevation.

b. depends only on the liquid and not on atmospheric pressure.

c. is the temperature at which the liquid boils under normal sea level pressure.

d. depends only on atmospheric pressure and not on the liquid.

6. The pressure of the atmosphere at sea level will support a column of mercury that is

a. 760 mm in height.

b. 22.4 mm in height.

c. 30.0 m in height.

d. 1.0 m in height.

7. The pressure in a liquid or in a gas is

a. the same at all levels.

b. exerted in all directions

c. exerted in only a downward direction.

d. independent of the weight of the liquid or gas.

8. SI units use the Pascal as the unit for pressure. One pascal is the same as

a. one newton/square centimeter.

b. one kilogram/square meter.

c. one newton/square meter.

d. one kilogram/square centimeter

9. Crystals that form with definite numbers of water molecules in their structure are called.

a. anhydrous.

b. hygroscopic.

c. hydrates.

d. deliquescent.

10. In solids the motion of the molecules is

a. totally absent

b. a vibration about a fixed position.

c. only in the horizontal plane.

d. only in the vertical plane

11. The heat of vaporization of a liquid

a. is only give for the boiling temperature.

b. is independent of any temperature change.

c. generally decreases with temperature increase.

d. generally increases with temperature increase.

12. The maximum temperature at which a gas can be liquefied by increasing the pressure on the gas is called its

a. vaporization temperature.

b. liquefaction temperature.

c. adiabatic temperature.

d. critical temperature

13. Foods cook faster in a pressure cooker because the foods cook

a. at a lower pressure

b. at a higher temperature.

c. with less heat loss.

d. at a lower temperature.

14. The temperature at which the vapor pressure of a liquid equals the existing atmospheric pressure at the surface of the liquid is called the

a. boiling point of the liquid.

b. saturation point of the atmosphere.

c. equilibrium vapor pressure temperature.

d. normal atmospheric temperature.

15. In a mixture of gases the total pressure of the gases is equal to the

a. sum of the pressures of the individual gases.

b. pressure of the gas that is most abundant.

c. vapor pressure of the individual liquids.

d. normal atmospheric pressure at sea level.

16. When an equilibrium between evaporation and condensation over the surface of a liquid occurs

a. no more evaporation from the liquid will occur.

b. the rates of condensation and evaporation are equal.

c. the vapor pressure of the liquid is equal to zero.

d. no more condensation of vapor to the liquid will occur.

17. Which of the following would not increase the rate of evaporation?

a. an increase in temperature

b. an increase in the presence of air currents

c. an increase in the surface area of the liquid

d. an increase in the amount of vapor over the liquid

18. Gases can be compressed by increasing the pressure, but liquids can be only very slightly compressed. This is because

a. there is less space between the particles in a liquid than a gas.

b. there are greater forces of repulsion in a liquid than in a gas.

c. the particles in a liquid are larger than in a gas.

d. gas particles are attracted to each other, while liquid particles are not.

19. The unusual contraction of ice as it melts is a direct result of

a. a greater density of ice compared to liquid water.

b. an increase in the attractive forces between particles.

c. the open crystalline structure of ice.

d. intermolecular repulsion of ice particles.

20. The property of absorbing enough moisture from the air to dissolve is called

a. hydration.

b. decrepitation.

c. effervescence.

d. deliquescence.

21. The heat of fusion of ice at 0°C 3.4 x 10² J/g. How much heat energy is absorbed by 6.2 /10² g of ice as it melts at 0.0°C?

22. The heat of vaporization of water is 2.3 x 10³ J/g at 100°C and 101.3 kPa. How much water can be evaporated at 100°C and 101.3 kPa if heat energy is added to a sample of water at 100°C at a rate of 5.0 x 10⁴ J/minute for 10.0 minutes?

23. Normal sea level pressure is 101.3 kPa, or760 mm of mercury. How many mm of mercury is equivalent to 1.0 kPa?

24. A block of wood has the dimensions of 1.00 m x 0.50 m x 0.10 m. The weight of the block of wood is 250 N. What is the pressure exerted by the block when resting on its edge (1.0 m x 0.10 m)?

25. Describe what happens within a liquid when its boiling point is reached. What conditions are required before a liquid begins to boil?

26. The pressure of a liquid in a container depends on

a. the depth of the liquid.

b. the volume of the liquid

c. the cross-sectional area of the container.

d. all of the above

27. The cooling effect accompanying the evaporation of a liquid is the result of

a. higher energy particles being added to the liquid.

b. lower energy particles being added to the liquid.

c. lower energy particles leaving the liquid.

d. higher energy particles leaving the liquid.

28. The vapor pressure of any liquid is equal to atmospheric pressure at

a. the liquids boiling temperature.

b. the temperature of 100°C.

c. any temperature above 0°C.

d. the liquid’s melting temperature.

29. What mass of ice at 0°C can be melted, heated to its boiling point, and completely boiled away by the addition of 3.0 x 10⁶ J? (The heat of fusion for ice is 3.4 x 10² J/g, and the heat of vaporization of water is 2.25 x 103 J/g. The specific heat of water is 4.2 H/g-°C.)

30. A layer of ice can withstand a pressure of only 6.0 N/m². A toboggan has a surface area of 0.6 m². What total weight (in newtons) could the toboggan have and still move across the ice without breaking through?

31. The heats of vaporization for different liquids vary as do their boiling temperatures. What can be inferred about these liquids from difference in these two properties?