Name:    Ch 14 - The Behavior of Gases

Matching (Value 10)

Match each item with the correct statement below.
 a. Boyle's law d. Graham's law b. Charles's law e. Gay-Lussac's law c. Dalton's law f. ideal gas law

1.

For a given mass of gas at constant temperature, the volume of the gas varies inversely with pressure.

2.

The volume of a fixed mass of gas is directly proportional to its Kelvin temperature, if the pressure is kept constant.

3.

The pressure of a gas is directly proportional to its Kelvin temperature if the volume is kept constant.

4.

P ´ V = n ´ R ´ T

5.

At constant volume and temperature, the total pressure exerted by a mixture of gases is equal to the sum of the partial pressures of the component gases.

6.

The rate at which a gas will effuse is inversely proportional to the square root of the gas’s molar mass.

Match each item with the correct statement below.
 a. effusion c. diffusion b. compressibility d. partial pressure

7.

a measure of how much the volume of matter decreases under pressure

8.

the pressure exerted by a gas in a mixture

9.

the escape of gas through a small hole in a container

10.

tendency of molecules to move to regions of lower concentration

Multiple Choice (Value 21)
Identify the letter of the choice that best completes the statement or answers the question.

11.

Why is a gas easier to compress than a liquid or a solid?
 a. Its volume increases more under pressure than an equal volume of liquid does. b. Its volume increases more under pressure than an equal volume of solid does. c. The space between gas particles is much less than the space between liquid or solid particles. d. The volume of a gas’s particles is small compared to the overall volume of the gas.

12.

How does the gas propellant move when an aerosol can is used?
 a. from a region of high pressure to a region of lower pressure b. from a region of high pressure to a region of equally high pressure c. from a region of low pressure to a region of higher pressure d. from a region of low pressure to a region of equally low pressure

13.

What happens to the temperature of a gas when it is compressed?
 a. The temperature increases. b. The temperature does not change. c. The temperature decreases. d. The temperature becomes unpredictable.

14.

As the temperature of the gas in a balloon decreases, which of the following occurs?
 a. The volume of the balloon increases. b. The average kinetic energy of the gas decreases. c. The gas pressure inside the balloon increases. d. all of the above

15.

Which of these changes would NOT cause an increase in the pressure of a contained gas?
 a. The volume of the container is increased. b. More of the gas is added to the container. c. The temperature is increased. d. The average kinetic energy of the gas in increased.

16.

The volume of a gas is doubled while the temperature is held constant. How does the gas pressure change?
 a. It is reduced by one half. b. It does not change. c. It is doubled. d. It varies depending on the type of gas.

17.

If a balloon is heated, what happens to the volume of the air in the balloon if the pressure is constant?
 a. It increases. c. It decreases. b. It stays the same. d. The change cannot be predicted.

18.

When the volume and number of particles of a gas are constant, which of the following is also constant?
 a. the sum of the pressure and temperature in kelvins b. the difference of the pressure and temperature in kelvins c. the product of the pressure and temperature in kelvins d. the ratio of the pressure and temperature in kelvins

19.

If a sealed syringe is plunged into cold water, in which direction will the syringe piston slide?
 a. in c. No movement will occur. b. out d. The direction cannot be predicted.

20.

What happens when a piston is used to decrease the volume of a contained gas?
 a. Fewer gas particles exert a force on the piston. b. The piston’s pressure on the gas becomes greater than the pressure exerted by the gas on the piston. c. Gas particles become compressed. d. Gas particles leak out of the container.

21.

If a sealed syringe is heated, in which direction will the syringe plunger move?
 a. out c. The plunger will not move. b. in d. The direction cannot be predicted.

22.

The combined gas law relates which of the following?
 a. pressure and volume only c. volume and temperature only b. temperature and pressure only d. temperature, pressure, and volume

23.

At a certain temperature and pressure, 0.20 mol of carbon dioxide has a volume of 3.1 L. A 3.1-L sample of hydrogen at the same temperature and pressure ____.
 a. has the same mass b. contains the same number of atoms c. has a higher density d. contains the same number of molecules

24.

Which of the following is constant for 1 mole of any ideal gas?
 a. PVT c. b. d. 25.

At low temperatures and pressures, how does the volume of a real gas compare with the volume of an ideal gas under the same conditions?
 a. It is greater. c. There is no difference. b. It is less. d. It depends on the type of gas.

26.

An ideal gas CANNOT be ____.
 a. condensed c. heated b. cooled d. compressed

27.

Under what conditions of temperature and pressure is the behavior of real gases most like that of ideal gases?
 a. low temperature and low pressure c. high temperature and low pressure b. low temperature and high pressure d. high temperature and high pressure

28.

If the atmospheric pressure on Mt. Everest is one-third the atmospheric pressure at sea level, the partial pressure of oxygen on Everest is ____.
 a. one-sixth its pressure at sea level c. one-half its pressure at sea level b. one-third its pressure at sea level d. equal to its pressure at sea level

29.

What happens to the partial pressure of oxygen in a sample of air if the temperature is increased?
 a. It increases. c. It decreases. b. It stays the same. d. The change cannot be determined.

30.

A breathing mixture used by deep-sea divers contains helium, oxygen, and carbon dioxide. What is the partial pressure of oxygen at 101.4 kPa if = 82.5 kPa and = 0.4 kPa?
 a. 82.9 kPa c. 18.5 kPa b. 19.3 kPa d. 101.0 kPa

31.

Which of the following gases will effuse the most rapidly?
 a. bromine c. ammonia b. chlorine d. hydrogen

32.

A gas occupies a volume of 140 mL at 35.0 C and 97 kPa. What is the volume of the gas at STP?

33.

A 10-g mass of krypton occupies 15.0 L at a pressure of 210 kPa. Find the volume of the krypton when the pressure is increased to 790 kPa.

34.

A gas storage tank has a volume of 3.5 10 m when the temperature is 27 C and the pressure is 101 kPa. What is the new volume of the tank if the temperature drops to –10 C and the pressure drops to 95 kPa?

35.

The gaseous product of a reaction is collected in a 25.0-L container at 27 C. The pressure in the container is 300.0 kPa and the gas has a mass of 96.0 g. How many moles of the gas are in the container?

36.

What is the pressure exerted by 32 g of O in a 22.0-L container at 30.0 C?

37.

A mixture of gases at a total pressure of 95 kPa contains N , CO , and O . The partial pressure of the CO is 24 kPa and the partial pressure of the N is 48 kPa. What is the partial pressure of the O ?

Essay (Value 2)

38.

How does the pressure of an enclosed gas in a rigid container change when the gas is heated? Explain why this change occurs.