A)
8.76 L
B)
17.5 L
C)
4.38 L
D)
19.1 L
E)
3.14 L
71. At 1000°C and 10. torr, the density of a certain element in the gaseous state is
. The element is:
A)
F
B)
He
C)
Na
D)
Zn
E)
Hg
72. Into a 2.22-liter container at 25°C are placed 1.23 moles of O2 gas and 3.20 moles of solid C
(graphite). If the carbon and oxygen react completely to form CO(g), what will be the final
pressure in the container at 25°C?
A)
27.1 atm
B)
13.5 atm
C)
2.27 atm
D)
35.2 atm
E)
none of these
73. Calcium hydride combines with water according to the equation:
Beginning with 84.0 g of CaH2 and 42.0 g of H2O, what volume of H2 will be produced at
273 K and a pressure of 1327 torr?
A)
29.9 L
B)
15.0 L
C)
L
D)
25.7 L
E)
none of these
5.39 102
74. What volume does 40.5 g of N2 occupy at STP?
A)
64.8 L
B)
1.81 L
C)
32.4 L
D)
50.7 L
E)
none of these
75. A mixture is prepared from 15.0 L of ammonia and 15.0 L chlorine measured at the same
conditions; these compounds react according to the following equation:
When the reaction is completed, what is the volume of each gas (NH3, Cl2, N2, and HCl,
respectively)? Assume the final volumes are measured under identical conditions.
A)
0.00 L, 5.00 L, 7.50 L, 45.0 L
B)
5.00 L, 0.00 L, 5.00 L, 30.0 L
C)
0.00 L, 0.00 L, 7.50 L, 45.0 L
D)
0.00 L, 0.00 L, 5.00 L, 30.0 L
E)
0.00 L, 10.0 L, 15.0 L, 90.0 L
76. An excess of sodium hydroxide is treated with 26.5 L of dry hydrogen chloride gas
measured at STP. What is the mass of sodium chloride formed?
A)
1.55 kg
B)
1.69 g
C)
0.138 kg
D)
69.1 g
E)
13.3 g
77. A 1.00-g sample of a gaseous compound of boron and hydrogen occupies 0.820 L at 1.00
atm and 3°C. What is the molecular formula for the compound?
A)
BH3
B)
B2H6
C)
B4H10
D)
B3H12
E)
B5H14
78. A mixture of KCl and KClO3 weighing 1.34 grams was heated; the dry O2 generated
occupied 143 mL at STP. What percent of the original mixture was KClO3, which
decomposes as follows:
A)
38.9%
B)
58.4%
C)
87.6%
D)
10.7%
E)
23.7%
79. Given the equation:
A 3.00-g sample of KClO3 is decomposed and the oxygen at 24.0°C and 0.717 atm is
collected. What volume of oxygen gas will be collected assuming 100% yield?
A)
mL
B)
mL
C)
mL
D)
mL
E)
none of these
80. If M is the molar mass, R the gas constant, T the temperature, and P its pressure, which of
the following expressions represents the density of a gas?
A)
B)
C)
D)
E)
81. One way to isolate metals from their ores is to react the metal oxide with carbon as shown in
the following reaction:
8.32 102
1.01 102
1.25 103
5.55 102
If 34.08 g of a metal oxide reacted with excess carbon and 4.37 L of CO2 formed at 100°C
and 1.50 atm, what is the identity of the metal?
A)
Hg
B)
Mg
C)
Cu
D)
Cd
E)
Zn
82. The standard temperature for gases is
A)
100°C
B)
0°C
C)
32°C
D)
212°F
E)
0°F
83. Standard pressure for gases is
A)
0 atm
B)
1 atm
C)
100 atm
D)
dependent upon temperature
E)
none of the above
84. Determine the partial pressure of the hydrogen gas in this mixture.
A)
562 torr
B)
580 torr
C)
598 torr
D)
616 torr
E)
634 torr
85. Determine the number of moles of hydrogen gas present in the sample.
A)
42 mol
B)
0.82 mol
C)
1.3 mol
D)
0.056 mol
E)
22 mol
86. A 142-mL sample of gas is collected over water at 22°C and 753 torr. What is the volume of
the dry gas at STP? (The vapor pressure of water at 22°C = 20. torr)
A)
122 mL
B)
162 mL
C)
136 mL
D)
111 mL
E)
none of these
87. A vessel with a volume of 26.9 L contains 2.80 g of nitrogen gas, 0.605 g of hydrogen gas,
and 79.9 g of argon gas. At 25°C, what is the pressure in the vessel?
A)
75.5 atm
B)
0.183 atm
C)
2.55 atm
D)
2.18 atm
E)
58.7 atm
88. Oxygen gas, generated by the reaction is collected over
water at 27°C in a 1.55-L vessel at a total pressure of 1.00 atm. (The vapor pressure of H2O
at 27°C is 26.0 torr.) How many moles of KClO3 were consumed in the reaction?
A)
0.0608 moles
B)
0.0912 moles
C)
0.0405 moles
D)
0.0434 moles
E)
1.50 moles
89. Calculate the total pressure.
A)
1.20 atm
B)
1.50 atm
C)
1.88 atm
D)
2.01 atm
E)
none of these
90. Calculate the ratio of PHe : PAr.
A)
1/1.22
B)
1.22/1
C)
1/12.2
D)
12.2/1
E)
none of these
91. The valve between a 5-L tank containing a gas at 9 atm and a 10-L tank containing a gas at
6 atm is opened. Calculate the final pressure in the tanks.
A)
3 atm
B)
4 atm
C)
7 atm
D)
15 atm
E)
none of these
92. A balloon contains an anesthetic mixture of cyclopropane (cp) and oxygen (O2) at 171 torr
and 570. torr, respectively. What is the ratio of the number of moles of cyclopropane to
moles of oxygen?
A)
3.33
B)
0.230
C)
0.300
D)
0.390
E)
0.460
93. A gaseous mixture containing 1.5 mol Ar and 3.5 mol CO2 has a total pressure of 7.3 atm.
What is the partial pressure of CO2?
A)
2.2 atm
B)
1.4 atm
C)
17 atm
D)
5.1 atm
E)
7.3 atm
94. The valve between the 2.00-L bulb, in which the gas pressure is 1.80 atm, and the 3.00-L
bulb, in which the gas pressure is 3.00 atm, is opened. What is the final pressure in the two
bulbs, the temperature remaining constant?
A)
0.720 atm
B)
2.28 atm
C)
2.52 atm
D)
1.80 atm
E)
2.40 atm
95. The partial pressures of CH4, N2, and O2 in a sample of gas were found to be 135 mmHg,
508 mmHg, and 571 mmHg, respectively. Calculate the mole fraction of nitrogen.
A)
20.4
B)
0.470
C)
0.418
D)
0.751
E)
0.359
96. Dalton’s law of partial pressures states that:
A)
Equal amounts of gases occupy the same volume at constant temperature and
pressure.
B)
The volume of a fixed amount of gas is inversely proportional to its pressure at
constant temperature.
3.00 L 2.00 L
C)
The volume of a fixed amount of gas is directly proportional to its temperature in
Kelvin at constant pressure.
D)
The total pressure of a mixture of gases is the sum of the partial pressure of all of
the gaseous compounds.
E)
The rates of effusion of gases are inversely proportional to the square roots of their
molar masses.
97. Which of the following is not a postulate of the kinetic molecular theory?
A)
Gas particles have most of their mass concentrated in the nucleus of the atom.
B)
The moving particles undergo perfectly elastic collisions with the walls of the
container.
C)
The forces of attraction and repulsion between the particles are insignificant.
D)
The average kinetic energy of the particles is directly proportional to the absolute
temperature.
E)
All of the above are postulates of the kinetic molecular theory.
98. Consider the following gas samples:
Sample A
Sample B
S2(g)
O2(g)
n = 1 mol
n = 2 mol
T = 800 K
T = 400 K
P = 0.20 atm
P = 0.40 atm
Which of the following statements is false?
A)
The volume of sample A is twice the volume of sample B.
B)
The average kinetic energy of the molecules in sample A is twice the average
kinetic energy of the molecules in sample B.
C)
The fraction of molecules in sample A, having a kinetic energy greater than some
high fixed value, is larger than the fraction of molecules in sample B, having
kinetic energies greater than that same high fixed value.
D)
The mean square velocity of molecules in sample A is twice as large as the mean
square velocity of molecules in sample B.
E)
Assuming identical intermolecular forces in the two samples, sample A should be
more nearly ideal than sample B.
99. What would happen to the average kinetic energy of the molecules of a gas sample if the
temperature of the sample increased from 20°C to 40°C?
A)
It would double.
B)
It would increase.
C)
It would decrease.
D)
It would become half its value.
E)
Two of these.
100. In the kinetic molecular theory we assume an ideal gas has no mass.
101. At 200 K, the molecules or atoms of an unknown gas, X, have an average velocity equal to
that of Ar atoms at 400 K. What is X? (Assume ideal behavior.)
A)
He
B)
CO
C)
HF
D)
HBr
E)
F2
102. Which of the following is not an assumption of the kinetic molecular theory for a gas?
A)
Gases are made up of tiny particles in constant chaotic motion.
B)
Gas particles are very small compared to the average distance between the
particles.
C)
Gas particles collide with the walls of their container in elastic collisions.
D)
The average velocity of the gas particles is directly proportional to the absolute
temperature.
E)
All of the above are assumptions of the kinetic molecular theory.
103. Use the kinetic molecular theory of gases to predict what would happen to a closed sample
of a gas whose temperature increased while its volume decreased.
A)
Its pressure would decrease.
B)
Its pressure would increase.
C)
Its pressure would hold constant.
D)
The number of moles of the gas would decrease.
E)
The average kinetic energy of the molecules of the gas would decrease.
104. Calculate the root mean square velocity for the O2 molecules in a sample of O2 gas at
11.8°C. (R = 8.3145 J/K mol)
A)
95.91 m/s
B)
14.90 m/s
C)
471.2 m/s
D)
272.0 m/s
E)
m/s
105. Which of the following is true about the kinetic molecular theory?
A)
The volume of a gas particle is considered to be small – about 0.10 mL.
B)
Pressure is due to the collisions of the gas particles with the walls of the container.
C)
Gas particles repel each other, but do not attract one another.
D)
Adding an ideal gas to a closed container will cause an increase in temperature.
E)
At least two of the above statements are correct.
106. Consider the following containers, one with helium at 27°C and the other with argon at
27°C.
Which of the following statements are true?
A)
The speed of each atom of helium is 926 m/s.
B)
The rms speed of the He and the Ar atoms are the same.
C)
The average kinetic energy of the two samples are equal.
D)
All of the above are true.
E)
None of the above are true.
107. Which of the following statements is true concerning ideal gases?
A)
The temperature of the gas sample is directly related to the average velocity of the
gas particles.
B)
At STP, 1.0 L of Ar(g) contains about twice the number of atoms as 1.0 L of Ne(g)
since the molar mass of Ar is about twice that of Ne.
8.973 1026
C)
A gas exerts pressure as a result of the collisions of the gas molecules with the
walls of the container.
D)
The gas particles in a sample exert attraction for one another.
E)
All of the above are false.
108. At the same temperature, lighter molecules have a higher average kinetic energy than
heavier molecules.
109. According to the postulates of the kinetic theory of gases, the average speed of the
molecules of a given gas is proportional to the
A)
absolute temperature squared
B)
square root of the absolute temperature
C)
absolute temperature
D)
Celsius temperature squared
E)
reciprocal of the absolute temperature
110. Which statement is inconsistent with the kinetic theory of an ideal gas?
A)
The forces of repulsion between gas molecules are very weak or negligible.
B)
Most of the volume occupied by a gas is empty space.
C)
When two gas molecules collide, they both gain kinetic energy.
D)
The average kinetic energy of a gas is proportional to the absolute temperature.
E)
Gas molecules move in a straight line between collisions.
111. Which of the following is included as a postulate in the kinetic molecular theory of an ideal
gas?
A)
The distance between gas molecules is small compared with the size of the
molecule.
B)
All collisions between molecules are elastic.
C)
In an average collision between molecules, both molecules have the same kinetic
energy.
D)
All molecules move randomly in zigzag directions.
E)
All the molecules have the same velocity.
112. All the following are postulates of the kinetic-molecular theory of gases except:
A)
The collisions between molecules are elastic.
B)
The gas molecules are in constant motion.
C)
At a constant temperature, each molecule has the same kinetic energy.
D)
The volumes of the molecules are negligible compared with the volume of the
container.
E)
The gas molecules are in rapid motion.
113. Graham’s law states that:
A)
Equal amounts of gases occupy the same volume at constant temperature and
pressure.
B)
The volume of a fixed amount of gas is inversely proportional to its pressure at
constant temperature.
C)
The volume of a fixed amount of gas is directly proportional to its temperature in
Kelvin at constant pressure.
D)
The total pressure of a mixture of gases is the simple sum of the partial pressure of
all of the gaseous compounds.
E)
The rates of effusion of gases are inversely proportional to the square roots of their
molar masses.
114. Which of the following would have a higher rate of effusion than C2H2?
A)
N2
B)
O2
C)
Cl2
D)
CH4
E)
CO2
115. A sample of N2 gas is contaminated with a gas (A) of unknown molar mass. The partial
pressure of each gas is known to be 200. torr at 25°C. The gases are allowed to effuse
through a pinhole, and it is found that gas A escapes at 4 times the rate of N2. The molar
mass of gas A is:
A)
1.75 g/mol
B)
112 g/mol
C)
7.01 g/mol
D)
448 g/mol
E)
none of these
116. The rate of effusion of an unknown gas was measured and found to be 11.9 mL/min. Under
identical conditions, the rate of effusion of pure oxygen (O2) gas is 14.0 mL/min. Based on
this information, the identity of the unknown gas could be:
A)
B)
C)
D)
E)
none of these
117. Calculate the ratio of the effusion rates of N2 and N2O.
A)
0.637
B)
1.57
C)
1.25
D)
0.798
E)
1.61
118. Hydrogen and chlorine gases react to form HCl. You and a friend are on opposite sides of a
long hallway, you with H2 and your friend with Cl2. You both want to form HCl in the
middle of the room. Which of the following is true?
A)
You should release the H2 first.
B)
Your friend should release the Cl2 first.
C)
You both should release the gases at the same time.
D)
You need to know the length of the room to answer this question.
E)
You need to know the temperature to answer this question.
119. Order the following in increasing rate of effusion:
F2, Cl2, NO, NO2, CH4
A)
Cl2 < NO2 < F2 < NO < CH4
B)
Cl2 < F2 < NO2 < CH4 < NO
C)
CH4 < NO2 < NO < F2 < Cl2
D)
CH4 < NO < F2 < NO2 < Cl2
E)
F2 < NO < Cl2 < NO2 < CH4
120. The diffusion of a gas is faster than the effusion of a gas.
121. Complete the following: Because real gas particles have attraction for one another:
A)
Real gases act most ideally at STP.
B)
We assume gas particles have negligible (zero) volume.
C)
One mole of an ideal gas at STP has a volume of 22.4 L.
D)
Real gases act more ideally at higher temperatures and lower pressures.
E)
At least two of the above statements (A-D) correctly complete the statement.
122. The van der Waals equation, nRT = [P + a(n/V)2] (V – nb), incorporates corrections to the
ideal gas law in order to account for the properties of real gases. One of the corrections
accounts for
A)
the possibility of chemical reaction between molecules
B)
the finite volume of molecules
C)
the quantum behavior of molecules
D)
the fact that average kinetic energy is inversely proportional to temperature
E)
the possibility of phase changes when the temperature is decreased or the pressure
is increased
123. Which of the following properties of a real gas is related to the b coefficient in the van der
Waals equation?
A)
Real gases consist of molecules or atoms that have volume.
B)
The average speed of the molecules of a real gas increases with temperature.
C)
There are attractive forces between atoms or molecules of a real gas.
D)
The rate of effusion of a gas is inversely proportional to the square root of the
molecular weight of the gas.
E)
None of these.
124. Which of the following effects will make PV/nRT less than one for a real gas?
A)
The gas molecules are large enough to occupy a substantial amount of space.
B)
A large number of molecules have speeds greater than the average speed.
C)
The gas molecules have a very low molar mass.
D)
The gas molecules attract one another.
E)
None of these.
125. Which of the following statements is least likely to be true of a sample of nitrogen gas?
A)
Molecules of gaseous nitrogen are in constant random motion.
B)
The pressure exerted by gaseous nitrogen is due to collisions of the molecules with
the walls of the container.
C)
The average kinetic energy of the gaseous nitrogen is proportional to the absolute
temperature of the gas.
D)
Collisions between the gaseous molecules are elastic.
E)
The volume of the sample would be zero at –273°C.
126. Real gases are those that
A)
only behave ideally at high pressures or low temperatures
B)
deviate from ideal behavior
C)
are only available naturally in the earth’s atmosphere
D)
are called real gases because their behavior can easily be modeled
E)
have an even number of protons
127. Gases behave most ideally at STP.
128. The pressure a gas would exert under ideal conditions is always greater than the observed
pressure of a real gas.
129. Of the following real gases, which would be expected to have the lowest van der Waals
correction for intermolecular attractions?
A)
H2
B)
Cl2
C)
NH3
D)
O2
E)
not enough information to determine
130. What is the name for the lowest layer of the atmosphere, which is most influenced by
human activities?
A)
stratosphere
B)
mesosphere
C)
terrasphere
D)
troposphere
E)
ionosphere
131. Which of the following pollutant gases is not produced directly in a combustion engine?
A)
CO
B)
CO2
C)
O3
D)
NO
E)
NO2
132. Combustion of coal releases sulfur dioxide into the atmosphere. The following process
converts this gas into sulfuric acid, a component of acid rain.
If each tonne of coal produces L of sulfur dioxide (measured at STP), what mass
of sulfuric acid can result from combustion of each tonne of coal? (1 tonne = 1000 kg)
A)
kg H2SO4
B)
kg H2SO4
C)
kg H2SO4
D)
kg H2SO4
E)
kg H2SO4
133. A room is 16 ft 12 ft 12 ft. Would air enter or leave the room if the temperature changed
from 27°C to –3°C while the pressure remained constant? Determine the volume of the air
that moved in or out of the room.
1.30 104
2.85 101
2.86 104
5.69 107
5.69 101
1.14 102
134. Toy balloons are filled with hydrogen gas, at standard temperature, from a 10.0-liter
cylinder. The initial pressure of the gas in the cylinder is exactly 100 atm. Assuming each
balloon is filled to a volume of 1.0 liter at standard pressure, how many balloons could be
filled?
135. Calculate the density of F2 gas at 26°C and 755 torr.
136. If equal masses of hydrogen gas and helium gas are placed in the same container, determine
the ratio of partial pressure of hydrogen : partial pressure of helium.