58. A 1.00-L sample of a gas at STP has a mass of 1.16 g. The molar mass of the gas is
A)
5.18 g/mol.
B)
26.0 g/mol.
C)
22.4 g/mol.
D)
44.8 g/mol.
E)
193 g/mol.
59. The density of a gas is 1.96 g/L at STP. What is its molar mass?
A)
65.2 g/mol
B)
58.9 g/mol
C)
11.4 g/mol
D)
22.4 g/mol
E)
43.9 g/mol
60. A 1.50-L sample of a gas at STP has a mass of 4.75 g. What is one possible formula of the
gas?
A)
N2F4
B)
NF3
C)
NCl3
D)
NHF2
E)
NO2
61. At 540.5 mmHg and 40.2oC, a 8.18-L sample of a hydrocarbon gas has a mass of 9.98 g.
What is the formula of the gas?
A)
C2H2
B)
C3H8
C)
C3H6
D)
C2H4
E)
C2H6
62. It is found that at 27°C and 1.14 atm pressure, 2.22 L of gas has a mass of 3.49 g. Its molar
mass is
A)
46.2 g/mol.
B)
34.0 g/mol.
C)
29.4 g/mol.
D)
30.6 g/mol.
E)
39.8 g/mol.
63. At 28°C and 452 mmHg, an unknown pure gas has a density of 0.674 g/L. Which of the
following gases could be the unknown gas?
A)
F2
B)
C3H6
C)
N2O
D)
Ne
E)
N2
64. An unknown gaseous hydrocarbon consists of 85.63% carbon by mass. A 0.335-g sample
of the gas occupies a volume of 0.107 L at STP. What is the identity of the gas?
A)
C5H10
B)
C6H12
C)
C7H14
D)
CH2
E)
C4H8
65. An excess of sodium hydroxide is treated with 2.4 L of dry hydrogen iodide gas measured at
STP. What is the mass of sodium iodide is formed?
A)
1.20 g
B)
32.1 g
C)
16.1 g
D)
19 g
E)
360 g
Test Bank General Chemistry, 10th edition 19
66. The balanced chemical equation for the conversion of nitrogen to ammonia is:
2N2(g) + 3H2(g) → 2NH3(g)
Which of the following statements concerning this chemical equation is/are correct?
1.
In a 22.4 L container at standard temperature, 2 atm of nitrogen gas will react
with 3 atm of hydrogen gas to produce 2 atm of ammonia gas.
2.
At standard pressure and temperature, 22.4 L of nitrogen gas will react with
22.4 L of hydrogen gas to produce 22.4 L of ammonia gas.
3.
At standard pressure and temperature, 44.8 L of nitrogen gas will react with
67.2 L of hydrogen gas produce 22.4 L of ammonia gas .
A)
1 only
B)
2 only
C)
3 only
D)
1 and 2
E)
1, 2, and 3
67. A 22.4 L high pressure reaction vessel is charged with 0.3910 mol of iron powder and 1.20
atm of oxygen gas at standard temperature. On heating, the iron and oxygen react according
to the balanced reaction below.
4Fe(s) + 3O2(g) → 2Fe2O3(s)
After the reaction vessel is cooled, and assuming the reaction goes to completion, what
pressure of oxygen remains?
A)
0.903 atm
B)
1.196 atm
C)
0.675 atm
D)
0.293 atm
E)
0.196 atm
68. A high temperature reaction vessel is charged with 0.5860 mol of iron powder and 35.1 L of
oxygen gas at standard temperature at pressure. On heating, the iron and oxygen react
according to the balanced reaction below.
4Fe(s) + 3O2(g) → 2Fe2O3(s)
After the reaction vessel is cooled, and assuming the reaction goes to completion, what
volume of oxygen remains?
Test Bank General Chemistry, 10th edition 20
A)
25.3 L
B)
35.1 L
C)
17.6 L
D)
9.84 L
E)
0.293 L
69. What is the total volume of gases produced at 819 K and 1.00 atm pressure when 320 g of
ammonium nitrite undergoes the following decomposition reaction?
NH4NO2(s) → N2(g) + 2H2O(g)
A)
3 22.4 L
B)
22.4 L
C)
15 22.4 L
D)
5 22.4 L
E)
45 22.4 L
70. In which of the following reactions will the pressure increase upon completion of the
reaction at constant temperature?
A)
C(s) + O2(g) → CO2(g)
B)
2NO(g) + O2(g) → 2NO2(g)
C)
C2H6O(l) + 3O2(g) → 2CO2(g) + 3H2O(l)
D)
4NH3(g) + 5O2(g) → 4NO(g) + 6H2O(g)
E)
Cl2(g) + 3F2(g) → 2ClF3(g)
71. What volume of ammonia gas, measured at 660.3 mmHg and 58.2oC, is required to produce
6.46 g of ammonium sulfate according to the following balanced chemical equation?
2NH3(g) + H2SO4(aq) → (NH4)2SO4(s)
A)
0.000781 L
B)
0.00312 L
C)
0.765 L
D)
11.9 L
E)
3.06 L
Test Bank General Chemistry, 10th edition 21
72. If 379.8 mL of nitrogen gas, measured at 628.4 mmHg and 29.7oC, reacts with excess iodine
according to the following reaction, what mass of nitrogen triiodide is produced?
N2(g) + 3I2(s) → 2NI3(s)
A)
0.354 g
B)
4.99 g
C)
2.49 g
D)
9.98 g
E)
102 g
73. The following equation represents the partial combustion of methane, CH4.
2CH4(g) + 3O2(g) → 2CO(g) + 4H2O(g)
At constant temperature and pressure, what is the maximum volume of carbon monoxide
that can be obtained from 3.39 102 L of methane and 1.70 102 L of oxygen?
A)
5.09 102 L
B)
3.39 102 L
C)
1.19 103 L
D)
1.13 102 L
E)
6.78 102 L
74. Calcium nitrate will react with ammonium chloride at slightly elevated temperatures, as
represented in the equation below.
Ca(NO3)2(s) + 2NH4Cl(s) → 2N2O(g) + CaCl2(s) + 4H2O(g)
What is the maximum volume of N2O at STP that could be produced using a 3.40-mol
sample of each reactant?
A)
9.28 102 L
B)
152 L
C)
1.31 10–2 L
D)
76.2 L
E)
22.4 L
75. The following equation represents the oxidation of ammonia, NH3.
4NH3(g) + 5O2(g) → 4NO(g) + 6H2O(g)
At the same temperature and pressure, what is the maximum volume of nitrogen monoxide
that can be obtained from 4.55 102 L of ammonia and 4.55 102 L of oxygen?
A)
1.02 103 L
B)
2.02 102 L
C)
3.64 102 L
D)
9.10 102 L
E)
4.55 102 L
76. A vessel with a volume of 32.5 L contains 2.80 g of nitrogen gas, 0.403 g of hydrogen gas,
and 79.9 g of argon gas. At 25°C, what is the pressure in the vessel?
A)
63 atm
B)
256.2 atm
C)
1.73 atm
D)
0.145 atm
E)
0.87 atm
77. What is the volume occupied by a mixture of 0.522 mol of N2 and 0.522 mol of O2 gases at
0.83 atm and 42.7°C?
A)
9.79 102 L
B)
32.6 L
C)
2.20 L
D)
4.41 L
E)
16.3 L
78. In a mixture of argon and hydrogen, occupying a volume of 1.66 L at 910.0 mmHg and
54.9oC, it is found that the total mass of the sample is 1.13 g. What is the partial pressure of
argon?
A)
455 mmHg
B)
319 mmHg
C)
866 mmHg
D)
591 mmHg
E)
43.7 mmHg
79. The partial pressures of CH4, N2, and O2 in a sample of gas were found to be 155 mmHg,
476 mmHg, and 669 mmHg, respectively. What is the mole fraction of nitrogen?
A)
20.9
B)
0.880
C)
0.515
D)
0.410
E)
0.366
80. A 24.1-g mixture of nitrogen and carbon dioxide is found to occupy a volume of 15.1 L
when measured at 870.2 mmHg and 31.2oC. What is the mole fraction of nitrogen in this
mixture?
A)
0.539
B)
0.500
C)
0.461
D)
0.426
E)
0.574
81. A 19.3-g mixture of oxygen and argon is found to occupy a volume of 16.2 L when
measured at 675.9 mmHg and 43.4oC. What is the partial pressure of oxygen in this
mixture?
A)
401 mmHg
B)
338 mmHg
C)
274 mmHg
D)
437 mmHg
E)
239 mmHg
Test Bank General Chemistry, 10th edition 24
82. In a mixture of helium and chlorine, occupying a volume of 14.6 L at 871.7 mmHg and
28.6oC, it is found that the partial pressure of chlorine is 355 mmHg. What is the total mass
of the sample?
A)
50.6 g
B)
1.10 g
C)
21.1 g
D)
1.60 g
E)
19.5 g
83. What is the partial pressure of nitrogen in a container that contains 3.96 mol of oxygen,
7.49 mol of nitrogen, and 1.19 mol of carbon dioxide when the total pressure is 563 mmHg?
A)
53.0 mmHg
B)
819 mmHg
C)
176 mmHg
D)
334 mmHg
E)
563 mmHg
84. A sample of oxygen is collected over water at a total pressure of 690.7 mmHg at 19°C. The
vapor pressure of water at 19°C is 16.5 mmHg. The partial pressure of the O2 is
A)
0.9305 atm.
B)
0.9349 atm.
C)
0.9088 atm.
D)
1.070 atm.
E)
0.8871 atm.
85. A sample of hydrogen was collected by water displacement at 23.0°C and an atmospheric
pressure of 735 mmHg. Its volume is 568 mL. After water vapor is removed, what volume
would the hydrogen occupy at the same conditions of pressure and temperature? (The vapor
pressure of water at 23.0°C is 21 mmHg.)
A)
509 mL
B)
539 mL
C)
552 mL
D)
568 mL
E)
585 mL
86. A small amount wet of hydrogen gas (H2) can be prepared by the reaction of zinc with
excess hydrochloric acid and trapping the gas produced in an inverted tube initially filled
with water. If the total pressure of the gas in the collection tube is 729.7 mmHg at 25C,
what is the partial pressure of the hydrogen? The vapor pressure of water is 23.8 mmHg.
A)
705.9 mmHg
B)
753.5 mmHg
C)
729.7 mmHg
D)
31.51 mmHg
E)
47.60 mmHg
87. Which statement is inconsistent with the kinetic theory of an ideal gas?
A)
Most of the volume occupied by a gas is empty space.
B)
The forces of repulsion between gas molecules are very weak or negligible.
C)
Gas molecules move in a straight line between collisions.
D)
The average kinetic energy of a gas is proportional to the absolute temperature.
E)
The collisions between gas molecules are inelastic.
88. Which of the following is included as a postulate in the kinetic molecular theory of an ideal
gas?
A)
Collisions between molecules are all elastic.
B)
All molecules move randomly in zigzag directions.
C)
The distance between gas molecules is small compared with the size of the
molecule.
D)
All the molecules have the same velocity.
E)
In an average collision between molecules, both molecules have the same kinetic
energy.
Test Bank General Chemistry, 10th edition 26
89. Which of the following is not a postulates of the kinetic molecular theory of gases?
A)
The gas molecules are in constant motion.
B)
At a constant temperature, each molecule has the same kinetic energy.
C)
The collisions between molecules are elastic.
D)
The volumes of the molecules are negligible compared with the volume of the
container.
E)
The gas molecules are in rapid motion.
90. Which of the following statements is least likely to be true of a sample of nitrogen gas at
STP?
A)
Collisions between the gaseous molecules are elastic.
B)
The intermolecular forces between nitrogen molecules are not negligible.
C)
Molecules of gaseous nitrogen are in constant random motion.
D)
The average kinetic energy of the gaseous nitrogen is proportional to the absolute
temperature of the gas.
E)
The pressure exerted by gaseous nitrogen is due to collisions of the molecules with
the walls of the container.
91. If a sample of nitrogen gas in a sealed container of fixed volume is heated from 25°C to
150°C, the value of which of the following quantities will remain constant?
A)
the average speed of the molecules
B)
the density of the nitrogen
C)
the average intensity of a molecular collision with the walls of the container
D)
the average kinetic energy of the molecules
E)
the pressure of the gas
92. A sealed 22.4 L flask contains pure O2 at STP. A second sealed 22.4 L flask contains CH4 at
STP. Which of the following statements concerning the molecules in the flasks is/are true?
1.
The average kinetic energy of the O2 molecules is greater than the average
kinetic energy of CH4 molecules.
2.
The average velocity of the CH4 molecules is greater than the average velocity
of the O2 molecules.
3.
The volume occupied by the gas molecules in both flasks is small relative to
the total volume of the flasks.
Test Bank General Chemistry, 10th edition 27
A)
1 only
B)
2 only
C)
3 only
D)
2 and 3
E)
1, 2, and 3
93. Which of the following statements concerning a sample of oxygen gas at 1.00 atm pressure
is incorrect?
A)
The molecules are in constant rapid random motion.
B)
The pressure exerted by gaseous oxygen is due to the impact of the molecules with
the walls of the container.
C)
The average kinetic energy of the gaseous oxygen is inversely proportional to the
absolute temperature of the gas.
D)
The volume occupied by the oxygen molecules is negligible compared with the
size of the container.
E)
Collisions between the gaseous molecules are elastic.
94. According to the postulates of the kinetic theory of gases, the root-mean-square (rms) speed
of the molecules of a given gas is proportional to the
A)
reciprocal of the absolute temperature.
B)
Celsius temperature squared.
C)
absolute temperature.
D)
square root of the absolute temperature.
E)
absolute temperature squared.
95. At STP, as the molar mass of the molecules that make up a pure gas increases, the
A)
root mean square speed of the molecules increases.
B)
root mean square speed of the molecules decreases.
C)
root mean square speed of the molecules remains constant.
D)
root mean square speed increases to a maximum, then decreases.
E)
none of the above.
Test Bank General Chemistry, 10th edition 28
96. What is the ratio of the average speed of SO2 molecules to that of oxygen molecules at 298
K?
A)
:
B)
:
C)
2:1
D)
1:2
E)
1:1
97. Molecular speed distributions for a gas at two different temperatures are shown below.
Which of the following graphs correctly describes the distributions at the two temperatures,
where T2 > T1? NOTE: The small vertical lines indicate average speed.
A)
B)
C)
D)
E)
none of the above
98. Calculate the root-mean-square velocity for the O2 molecules in a sample of O2 gas at
24.3°C. (R = 8.3145 J/Kmol)
A)
15.22 m/s
B)
137.6 m/s
C)
277.9 m/s
D)
481.4 m/s
E)
9.167 1026 m/s
99. What is the ratio of the average speed of CH4 molecules to that of SO2 molecules at 298 K?
A)
1:1
B)
1:2
C)
1.4:1
D)
1:1.4
E)
2:1
100. Which of the following relates the rate of effusion of a gas to the square root of its molar
mass?
A)
Boyle’s law
B)
Graham’s law
C)
Charles’s law
D)
Dalton’s law
E)
Avogadro’s hypothesis
101. What is the ratio of the average rate of effusion of NOF(g) to that of HBr(g) at 400 K?
A)
81:49
B)
7:9
C)
49:81
D)
9:7
E)
The average rate of effusion is the same for the two gases.
102. Which of the following gases will have the slowest rate of effusion at constant temperature?
A)
H2
B)
F2
C)
Ne
D)
SO3
E)
CF4
103. The molar mass of an unknown gas was measured by an effusion experiment. It was found
that it took 63 s for the gas to effuse, whereas nitrogen gas required 48 s. The molar mass of
the gas is
A)
24 g/mol.
B)
37 g/mol.
C)
16 g/mol.
D)
32 g/mol.
E)
48 g/mol.
104. If 250 mL of methane, CH4, effuses through a small hole in 28 s, the time required for the
same volume of helium to pass through the hole under the same conditions will be
A)
56 s.
B)
7 s.
C)
1.8 s.
D)
14 s.
E)
112 s.
105. Under what set of conditions does HCl(g) deviate the most from ideal behavior?
A)
standard temperature and pressure
B)
high temperature and low pressure
C)
low temperature and high pressure
D)
low temperature and low pressure
E)
high temperature and high pressure
106. Real gases deviate from ideal behavior for two reasons: (1) real gas molecules have
intermolecular forces, and (2) real gas molecules have
A)
pressures within the chemical bonds.
B)
nonzero molecular volumes.
C)
ionization energies.
D)
molecular vibrations.
E)
a distribution of molecular speeds.
107. At 320 K and 16 atm pressure, the molar volume of ammonia, NH3, is about 10% less than
the molar volume of an ideal gas. The best explanation for actual volume being this much
smaller than ideal volume is that
A)
the intermolecular forces of attraction become significant at this temperature and
this pressure.
B)
the critical temperature and pressure of NH3 (405 K and 112 atm) are too close to
the actual temperature and pressure of the NH3 above.
C)
at this high temperature, a significant amount of NH3 decomposes to N2 and H2.
D)
ammonia is a real gas and not an ideal gas.
E)
the volume occupied by the NH3 molecules themselves is significant at this high
concentration.
108. Which of the following statements concerning gas molecules is incorrect?
A)
Attraction is greater between fast-moving molecules than between slow-moving
molecules.
B)
Real molecules have a weak attraction for each other.
C)
Real molecules have the greatest attraction for each other at low temperatures.
D)
Real molecules have the greatest attraction for each other at high pressures.
E)
Real molecules occupy a finite space.
109. Using the van der Waals equation, determine the pressure of 459.0 g of SO2(g) in a 4.40-L
vessel at 625 K. For SO2(g), a = 6.865 L2 • atm/mol2 and b = 0.05679 L/mol.
(R = 0.0821 L • atm/(K • mol))
A)
110 atm
B)
8.06 atm
C)
73.9 atm
D)
83.6 atm
E)
8.36 atm
110. In the van der Waals equation,
the effect of intermolecular forces is accounted for by
A)
T.
B)
V.
C)
b.
D)
a.
E)
P.
111. From a consideration of the van der Waals constants for water and sulfur dioxide,
a (atmL2/mol2)
b (L/mol)
H2O
5.54
0.0305
SO2
6.87
0.0568
we can conclude that
A)
H2O molecules are smaller and less attracted to each other than SO2 molecules.
B)
H2O molecules are larger and less attracted to each other than SO2 molecules.
C)
H2O molecules are larger and more attracted to each other than SO2 molecules.
D)
H2O molecules are equivalent to SO2 molecules in size and attraction to each
other.
E)
H2O molecules are smaller and more attracted to each other than SO2 molecules.