Name: 
 

Physical Characteristics of Gases


Multiple Choice
Identify the letter of the choice that best completes the statement or answers the question.
 

1. 
According to the kinetic-molecular theory, particles of matter
a.
are in constant motion.
c.
have different colors.
b.
have different shapes.
d.
are always fluid.
 

2. 
According to the kinetic-molecular theory, gases condense into liquids because of
a.
gravity.
c.
forces between molecules.
b.
atmospheric pressure.
d.
elastic collisions.
 

3. 
The kinetic-molecular theory explains the behavior of
a.
gases only.
c.
liquids and gases.
b.
solids and liquids.
d.
solids, liquids, and gases.
 

4. 
Which process can be explained by the kinetic-molecular theory?
a.
combustion
c.
condensation
b.
oxidation
d.
replacement reactions
 

5. 
According to the kinetic-molecular theory, which substances are made of particles?
a.
ideal gases only
c.
all matter
b.
all gases
d.
all matter except solids
 

6. 
The kinetic-molecular theory explains the properties of solids, liquids, and gases in terms of the energy of the particles and
a.
gravitational forces.
c.
diffusion.
b.
the forces that act between the particles.
d.
the mass of the particles.
 

7. 
According to the kinetic-molecular theory, particles of matter are in motion in
a.
gases only.
c.
solids, liquids, and gases.
b.
gases and liquids.
d.
solids only.
 

8. 
An ideal gas is an imaginary gas
a.
not made of particles.
b.
that conforms to all of the assumptions of the kinetic theory.
c.
whose particles have zero mass.
d.
made of motionless particles.
 

9. 
Unlike in an ideal gas, in a real gas
a.
all particles move in the same direction.
b.
all particles have the same kinetic energy.
c.
the particles cannot diffuse.
d.
the particles exert attractive forces on each other.
 

10. 
A real gas
a.
does not obey all the assumptions of the kinetic-molecular theory.
b.
consists of particles that do not occupy space.
c.
cannot be condensed.
d.
cannot be produced in scientific laboratories.
 

11. 
If two moving steel balls collide, their total energy after the collision is the same as before. This is an example of
a.
Boyle's law.
c.
an elastic collision.
b.
the law of gravity.
d.
both Boyle's law and Charles's law.
 

12. 
Which is NOT an assumption of the kinetic-molecular theory?
a.
Matter is composed of tiny particles.
b.
The particles of matter are in continual motion.
c.
The total kinetic energy of colliding particles remains constant.
d.
When individual particles collide, energy is transferred.
 

13. 
According to the kinetic-molecular theory, what is the most significant difference between gases and liquids?
a.
the shapes of the particles
b.
the mass of each particle
c.
the distance between the particles
d.
the type of collision that occurs between particles
 

14. 
According to the kinetic-molecular theory, particles of a gas
a.
attract each other but do not collide.
b.
repel each other and collide.
c.
neither attract nor repel each other but collide.
d.
neither attract nor repel each other and do not collide.
 

15. 
Which is an example of gas diffusion?
a.
inflating a flat tire
b.
the odor of perfume spreading throughout a room
c.
a cylinder of oxygen stored under high pressure
d.
All of the above
 

16. 
By which process do gases take the shape of their container?
a.
evaporation
c.
adhesion
b.
expansion
d.
diffusion
 

17. 
If a gas with an odor is released in a room, it quickly can be detected across the room because it
a.
diffuses.
c.
is compressed.
b.
is dense.
d.
condenses.
 

18. 
Which substance has the lowest density?
a.
H2O(g)
c.
Hg(l)
b.
H2O(l)
d.
Hg(g)
 

19. 
The density of a substance undergoes the greatest change when the substance changes from a
a.
liquid to a gas.
c.
solid to a liquid.
b.
liquid to a solid.
d.
a molecular solid to an ionic solid.
 

20. 
According to the kinetic-molecular theory, how does a gas expand?
a.
Its particles become larger.
b.
Collisions between particles become elastic.
c.
Its temperature rises.
d.
Its particles move greater distances.
 

21. 
Diffusion between two gases occurs most rapidly if the gases are at a
a.
high temperature and the molecules are small.
b.
low temperature and the molecules are large.
c.
low temperature and the molecules are small.
d.
high temperature and the molecules are large.
 

22. 
Which is an example of effusion?
a.
air slowly escaping from a pinhole in a tire
b.
the aroma of a cooling pie spreading across a room
c.
helium dispersing into a room after a balloon pops
d.
oxygen and gasoline fumes mixing in an automobile carburetor
 

23. 
What happens to the volume of a gas during compression?
a.
The volume increases.
b.
The volume decreases.
c.
The volume remains constant.
d.
It is impossible to tell because all gases are different.
 

24. 
Under which conditions do real gases most resemble ideal gases?
a.
low pressure and low temperature
c.
high pressure and high temperature
b.
low pressure and high temperature
d.
high pressure and low temperature
 

25. 
When does a real gas behave like an ideal gas?
a.
when the particles are far apart
b.
when the kinetic energy of the particles is low
c.
when the pressure is high
d.
when the gas is liquefied
 

26. 
Why doesn't a gas at a low temperature behave like an ideal gas?
a.
There is too much space between the particles.
b.
The attractive forces are too weak.
c.
The kinetic energy of the particles is too low.
d.
The particles undergo chemical reactions.
 

27. 
Which gases behave most like an ideal gas?
a.
gases composed of highly polar molecules
b.
gases composed of monatomic, nonpolar molecules
c.
gases composed of diatomic, polar molecules
d.
gases near their condensation temperatures
 

28. 
As a real gas deviates from ideal gas behavior, the particles
a.
move farther apart.
c.
collide more energetically.
b.
gain kinetic energy.
d.
experience stronger attractive forces.
 

29. 
The behavior of a gas under very high pressure is likely to
a.
conform to the assumptions of the kinetic-molecular theory.
b.
deviate from ideal gas behavior.
c.
show ideal gas behavior.
d.
be nonpolar.
 

30. 
Pressure is the force per unit
a.
volume.
c.
length.
b.
surface area.
d.
depth.
 

31. 
What is the SI unit of force?
a.
torr
c.
pound
b.
pascal
d.
newton
 

32. 
If force is held constant as surface area decreases, pressure
a.
remains constant.
b.
decreases.
c.
increases.
d.
increases or decreases, depending on the volume change.
 

33. 
What does the constant bombardment of gas molecules against the inside walls of a container produce?
a.
temperature
c.
pressure
b.
density
d.
diffusion
 

34. 
What is the definition of pressure?
a.
physicalcharacteris_files/i0350000.jpg
b.
physicalcharacteris_files/i0350001.jpg
c.
pressure = force ´ area
d.
physicalcharacteris_files/i0350002.jpg
 

35. 
Why does a can collapse when a vacuum pump removes air from the can?
a.
The inside and outside forces balance out and crush the can.
b.
The unbalanced outside force from atmospheric pressure crushes the can.
c.
The atmosphere exerts pressure on the inside of the can and crushes it.
d.
The vacuum pump creates a force that crushes the can.
 

36. 
What instrument measures atmospheric pressure?
a.
barometer
c.
vacuum pump
b.
manometer
d.
torrometer
 

37. 
What instrument measures the pressure of an enclosed gas?
a.
barometer
c.
vacuum pump
b.
manometer
d.
torrometer
 

38. 
A pressure of 745 mm Hg equals
a.
745 torr.
c.
1 pascal.
b.
1 torr.
d.
745 pascal.
 

39. 
Convert the pressure 0.75 atm to mm Hg.
a.
101.325 mm Hg
c.
570 mm Hg
b.
430 mm Hg
d.
760 mm Hg
 

40. 
Convert the pressure 0.840 atm to mm Hg.
a.
365 mm Hg
c.
638 mm Hg
b.
437 mm Hg
d.
780 mm Hg
 

41. 
Convert the pressure 0.600 atm to mm Hg.
a.
325 mm Hg
c.
572 mm Hg
b.
456 mm Hg
d.
708 mm Hg
 

42. 
Convert the pressure 2.50 atm to kPa.
a.
1 kPa
c.
760 kPa
b.
253 kPa
d.
1000 kPa
 

43. 
Convert the pressure 1.30 atm to kPa.
a.
2 kPa
c.
132 kPa
b.
115 kPa
d.
245 kPa
 

44. 
Standard temperature is exactly
a.
100ºC.
c.
0ºC.
b.
273ºC.
d.
0 K.
 

45. 
Standard pressure is the pressure exerted by a column of mercury exactly
a.
273 mm high.
c.
760 cm high.
b.
760 mm high.
d.
1.00 m high.
 

46. 
Standard pressure is exactly
a.
1 atm.
c.
101.325 atm.
b.
760 atm.
d.
101 atm.
 

47. 
If the height of mercury in a barometer at 0ºC is less than 760 mm Hg, then
a.
the atmospheric pressure is less than standard atmospheric pressure.
b.
the atmospheric pressure is greater than standard atmospheric pressure.
c.
the atmospheric pressure is equal to standard atmospheric pressure.
d.
the atmospheric pressure cannot be determined.
 

48. 
If the pressure and temperature of a gas are held constant and some gas is added to the container or some is allowed to escape, a change in which of the following can be observed?
a.
kinetic energy
c.
elasticity
b.
volume
d.
fluidity
 

49. 
If the temperature of a fixed quantity and volume of gas changes, what also changes?
a.
pressure
c.
mass
b.
density
d.
formula
 

50. 
To observe the effects of changing pressure on the volume of a gas, factors that must be kept constant are the gas's temperature and
a.
density.
c.
elasticity.
b.
quantity.
d.
All of the above
 

51. 
To study the relationship between the temperature and volume of a gas, which factor must be held constant?
a.
elasticity
c.
kinetic energy
b.
fluidity
d.
pressure
 

52. 
If the temperature of a fixed quantity of gas decreases and the pressure remains unchanged,
a.
its volume increases.
c.
its volume decreases.
b.
its volume is unchanged.
d.
its density decreases.
 

53. 
Suppose the temperature of the air in a balloon is increased. If the pressure remains constant, what quantity must change?
a.
volume
c.
compressibility
b.
number of molecules
d.
adhesion
 

54. 
Two gases have the same temperature but different pressures. The kinetic-molecular theory does NOT predict that
a.
molecules in both gases have the same average kinetic energies.
b.
molecules in the low-pressure gas travel farther before they collide with other molecules.
c.
both gases have the same densities.
d.
all collisions of the molecules are elastic.
 

55. 
Why does the air pressure inside the tires of a car increase when the car is driven?
a.
Some of the air has leaked out.
b.
The air particles collide with the tire after the car is in motion.
c.
The air particles inside the tire increase their speed because their temperature rises.
d.
The atmosphere compresses the tire.
 

56. 
If the temperature of a container of gas remains constant, how could the pressure of the gas increase?
a.
The mass of the gas molecules increases.
b.
The diffusion of the gas molecules increases.
c.
The size of the container increases.
d.
The number of gas molecules in the container increases.
 

57. 
The gas pressure inside a container decreases when
a.
the number of gas molecules is increased.
b.
the number of gas molecules is decreased.
c.
the temperature is increased.
d.
the number of molecules is increased and the temperature is increased.
 

58. 
If the temperature remains constant, V and P represent the original volume and pressure, and V' and P' represent the new volume and pressure, what is the mathematical expression for Boyle's law?
a.
P'V = V'P
c.
V'P' = VP
b.
VV' = PP'
d.
physicalcharacteris_files/i0590000.jpg
 

59. 
Pressure and volume changes at a constant temperature can be calculated using
a.
Boyle's law.
c.
Kelvin's law.
b.
Charles's law.
d.
Dalton's law.
 

60. 
The volume of a gas is 400.0 mL when the pressure is 1.00 atm. At the same temperature, what is the pressure at which the volume of the gas is 2.0 L?
a.
0.5 atm
c.
0.20 atm
b.
5.0 atm
d.
800 atm
 

61. 
The pressure of a sample of helium is 2.0 atm in a 200-mL container. If the container is compressed to 10 mL without changing the temperature, what is the new pressure?
a.
200 atm
c.
100 atm
b.
0.10 atm
d.
40. atm
 

62. 
A sample of oxygen occupies 560. mL when the pressure is 800.00 mm Hg. At constant temperature, what volume does the gas occupy when the pressure decreases to 700.0 mm Hg?
a.
80.0 mL
c.
600. mL
b.
490. mL
d.
640. mL
 

63. 
A sample of argon gas at standard pressure occupies 1000. mL. At constant temperature, what volume does the gas occupy if the pressure increases to 800. mm Hg?
a.
500. mL
c.
950. mL
b.
760. mL
d.
1053. mL
 

64. 
A sample of gas collected at 750. mm Hg occupies 250. mL. At constant temperature, what pressure does the gas exert if the volume increases to 300. mL?
a.
50. mm Hg
c.
625. mm Hg
b.
550. mm Hg
d.
900. mm Hg
 

65. 
At 710. mm Hg, a sample of nitrogen gas occupies 625 mL. What volume does the gas occupy if the temperature remains constant and the pressure increases to 760. mm Hg?
a.
135 mL
c.
600 mL
b.
584 mL
d.
669 mL
 

66. 
A 425 mL sample of gas is collected at 780. mm Hg. If the temperature remains constant and the pressure falls to 680. mm Hg, what is the new volume?
a.
325 mL
c.
488 mL
b.
370 mL
d.
525 mL
 

67. 
If V is the original volume, V' is the new volume, T is the original Kelvin temperature, and T' is the new Kelvin temperature, how is Charles's law expressed mathematically?
a.
physicalcharacteris_files/i0680000.jpg
c.
physicalcharacteris_files/i0680001.jpg
b.
physicalcharacteris_files/i0680002.jpg
d.
physicalcharacteris_files/i0680003.jpg
 

68. 
The volume of a gas is 5.0 L when the temperature is 5.0ºC. If the temperature is increased to 10.0ºC without changing the pressure, what is the new volume?
a.
2.5 L
c.
5.1 L
b.
4.8 L
d.
10.0 L
 

69. 
At 7.0ºC, the volume of a gas is 49 mL. At the same pressure, its volume is 74 mL at what temperature?
a.
3.0ºC
c.
120ºC
b.
16ºC
d.
150ºC
 

70. 
A 180.0 mL volume of gas is measured at 87.0ºC. If the pressure remains unchanged, what is the volume of the gas at standard temperature?
a.
0.0 mL
c.
136 mL
b.
0.5 mL
d.
410 mL
 

71. 
The volume of a gas is 93 mL when the temperature is 91ºC. If the temperature is reduced to 0ºC without changing the pressure, what is the new volume of the gas?
a.
70 mL
c.
120 mL
b.
100 mL
d.
273 mL
 

72. 
The volume of a gas is 400. mL at 30.0ºC. If the temperature is increased to 50.0ºC without changing the pressure, what is the new volume of the gas?
a.
375 mL
c.
426 mL
b.
400 mL
d.
600 mL
 

73. 
If a gas occupies 950.0 mL at standard temperature, what volume does it occupy at 25.00ºC if the pressure remains constant?
a.
870.0 mL
c.
1000.0 mL
b.
966.0 mL
d.
1037 mL
 

74. 
If the temperature of 50.0 L of a gas at 40.0ºC falls by 10.0Cº, what is the new volume of the gas if the pressure is constant?
a.
45.0 L
c.
52.0 L
b.
48.4 L
d.
55.0 L
 

75. 
Why would the pressure of a sample of gas at a constant volume fall 75 mm Hg?
a.
The container exploded.
c.
The temperature decreased.
b.
The temperature increased.
d.
Fewer particles were present.
 

76. 
On a cold winter morning when the temperature is –13ºC, the air pressure in an automobile tire is 1.5 atm. If the volume does not change, what is the pressure after the tire has warmed to 15ºC?
a.
–1.5 atm
c.
3.0 atm
b.
1.7 atm
d.
19.5 atm
 

77. 
The pressure of a sample of gas of constant volume is 2.0 atm at 30.ºC. What is the pressure of this sample at 20.ºC?
a.
1.0 atm
c.
2.1 atm
b.
1.9 atm
d.
20 atm
 

78. 
The pressure of a 1000. mL sample of gas at 10.0ºC increases from 700. mm Hg to 900. mm Hg. If the volume is unchanged, what is the new temperature?
a.
0ºC
c.
30ºC
b.
24ºC
d.
91ºC
 

79. 
The pressure of a sample of gas at a constant volume is 8.0 atm at 70.ºC. What is the pressure at 20.ºC?
a.
0.16 atm
c.
9.4 atm
b.
6.8 atm
d.
58 atm
 

80. 
The temperature of a sample of gas at 4.0 atm and 15.ºC increases to 30.ºC. If the volume is unchanged, what is the new gas pressure?
a.
3.8 atm
c.
8 atm
b.
4.2 atm
d.
19 atm
 

81. 
The pressure of a sample of gas increases from 450. mm Hg to 500. mm Hg. If the volume is constant and the temperature of the gas was 0.0ºC, what is the new gas temperature?
a.
–30.ºC
c.
50.ºC
b.
30.ºC
d.
273ºC
 

82. 
As the temperature of a sample of gas falls from 45.0ºC to 30.0ºC, its pressure falls to 300. mm Hg. If the volume did not change, what was the original gas pressure?
a.
285 mm Hg
c.
400. mm Hg
b.
315 mm Hg
d.
615 mm Hg
 

83. 
A sample of gas at 6.0 atm and 5.0ºC increases in temperature to 35ºC. If the volume is unchanged, what is the new pressure?
a.
5.4 atm
c.
36 atm
b.
6.6 atm
d.
42 atm
 

84. 
If V, P, and T represent the original volume, pressure, and temperature in the correct units, and V', P', and T' represent the new conditions, what is the combined gas law?
a.
physicalcharacteris_files/i0850000.jpg
c.
physicalcharacteris_files/i0850001.jpg
b.
physicalcharacteris_files/i0850002.jpg
d.
physicalcharacteris_files/i0850003.jpg
 

85. 
The volume of a sample of oxygen is 300.0 mL when the pressure is 1 atm and the temperature is 27.0ºC. At what temperature is the volume 1.00 L and the pressure 0.500 atm?
a.
22.0ºC
c.
0.50 K
b.
45.0ºC
d.
227ºC
 

86. 
Suppose that the pressure of 1.00 L of gas is 380. mm Hg when the temperature is 200. K. At what temperature is the volume 2.00 L and the pressure 0.750 atm?
a.
1.00 K
c.
219ºC
b.
600. K
d.
67.0 K
 

87. 
The volume of a gas collected when the temperature is 11.0ºC and the pressure is 710 mm Hg measures 14.8 mL. What is the calculated volume of the gas at 20.0ºC and 740 mm Hg?
a.
7.8 mL
c.
14.6 mL
b.
13.7 mL
d.
15 mL
 

88. 
The volume of a sample of hydrogen is 798 mL and it exerts 621 mm Hg pressure at 5.00ºC. What volume does it occupy at standard temperature and pressure?
a.
520. mL
c.
745 mL
b.
640. mL
d.
960 mL
 

89. 
A 30.-L sample of gas exerts 200. mm Hg pressure at 10ºC. What volume does the gas have at 300. mm Hg and 25ºC?
a.
9.0 L
c.
21 L
b.
17 L
d.
42 L
 

90. 
At 0.500 atm and 15.0ºC a sample of gas occupies 120. L. What volume does it occupy at 0.250 atm and 10.0ºC?
a.
60 L
c.
236 L
b.
111 L
d.
480 L
 

91. 
A 70.0 L sample of gas at 20.0ºC and 600. mm Hg expands to 90.0 L at 15.0ºC. What is the new gas pressure?
a.
318 mm Hg
c.
583 mm Hg
b.
459 mm Hg
d.
710 mm Hg
 

92. 
A 75.0 mL sample of gas exerts 200. mm Hg pressure at 30ºC. What pressure does it exert at 35.0ºC if the volume expands to 80.0 mL?
a.
90.0 mm Hg
c.
190 mm Hg
b.
161 mm Hg
d.
219 mm Hg
 

93. 
A 150.0 L sample of gas is collected at 1.20 atm and 25ºC. What volume does the gas have at 1.50 atm and 20.0ºC?
a.
94 L
c.
143 L
b.
120 L
d.
183 L
 

94. 
Who developed the concept that the total pressure of a mixture of gases is the sum of their  partial pressures?
a.
Charles
c.
Kelvin
b.
Boyle
d.
Dalton
 

95. 
To correct for the partial pressure of water vapor, the vapor pressure of H2O at the collecting temperature is
a.
divided by 22.4.
c.
subtracted from the total gas pressure.
b.
multiplied by 22.4.
d.
added to the total gas pressure.
 

96. 
Three samples of gas each exert 740. mm Hg in separate 2 L containers. What pressure do they exert if they are all placed in a single 2 L container?
a.
247 mm Hg
c.
1480 mm Hg
b.
740 mm Hg
d.
2220 mm Hg
 

97. 
A mixture of four gases exerts a total pressure of 860 mm Hg. Gases A and B each exert 220 mm Hg. Gas C exerts 110 mm Hg. What pressure is exerted by gas D?
a.
165 mm Hg
c.
860 mm Hg
b.
310 mm Hg
d.
cannot be determined
 

98. 
If five gases in a cylinder each exert 1 atm, what is the total pressure exerted by the gases?
a.
0.2 atm
c.
1 atm
b.
0.5 atm
d.
5 atm
 
 
         Water Vapor Pressure
Temperature (ºC)
Pressure (mm Hg)
0
      4.6
5
      6.5
10
      9.2
15
      12.8
20
      17.5
25
      23.8
30
      31.8
35
      42.2
40
      55.3
50
      92.5
 

99. 
What is the partial pressure of water vapor in oxygen gas collected by water displacement at 10ºC and 750 mm Hg?
a.
9.2 mm Hg
c.
750 mm Hg
b.
740.8 mm Hg
d.
759.2 mm Hg
 

100. 
A sample of gas is collected by water displacement at 600.0 mm Hg and 30ºC. What is the partial pressure of the gas?
a.
568.2 mm Hg
c.
630 mm Hg
b.
600.0 mm Hg
d.
631.8 mm Hg
 

101. 
A sample of nitrogen is collected by water displacement at 730.0 mm Hg and 20ºC. What is the partial pressure of the nitrogen?
a.
17.5 mm Hg
c.
717.2 mm Hg
b.
712.5 mm Hg
d.
747.5 mm Hg
 

Short Answer
 

102. 
Why are gases described as fluid?
 

103. 
Why must a barometer be open to the air at one end and closed at the other?
 

104. 
What are standard temperature and pressure? Why was a standard needed?
 

Essay
 

105. 
Explain how a barometer works.
 



 
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