Multiple Choice
Identify the
letter of the choice that best completes the statement or answers the question.
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1.
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Convert 82.1 kPa to mm Hg. (1 atm = 760 mm Hg = 101.325 kPa) a. | 0.810 mm
Hg | b. | 10.9 mm
Hg | c. | 616 mm
Hg | d. | 2.40
x 103
mm Hg | e. | 6.32 x 106 mm Hg | | |
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2.
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At
constant temperature, 14.0 L of O2 at 0.882 atm is compressed to 1.75 L. What is the final
pressure of O2? a. | 0.111 atm | b. | 0.142
atm | c. | 7.06
atm | d. | 21.6
atm | e. | 27.8
atm | | |
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3.
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The
lid is tightly sealed on a rigid flask containing 3.50 L H2 at 17 °C and 0.913 atm.
If the flask is heated to 71 °C, what is the pressure in the flask? a. | 0.770
atm | b. | 1.08
atm | c. | 2.95
atm | d. | 3.81
atm | e. | 13.3
atm | | |
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4.
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A
balloon is filled with He gas to a volume of 3.22 L at 32 °C. The balloon is placed in liquid nitrogen until its
temperature reaches -132 °C. Assuming the pressure remains constant, what is the volume of the
cooled balloon? a. | 0.628
L | b. | 0.781
L | c. | 1.24
L | d. | 1.49
L | e. | 6.96
L | | |
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5.
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A
0.225-L flask contains CH4 at 27 °C and 318 mm Hg. What is the pressure of the CH4 if the
volume is increased to 0.500 L and the temperature increased to 95 °C? a. | 117 mm
Hg | b. | 176 mm
Hg | c. | 503 mm
Hg | d. | 508 mm
Hg | e. | 867 mm
Hg | | |
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6.
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If a
3.44-L flask of SO2 at 1.65 atm contains the same number of molecules as a 5.00-L flask of
H2 at -7 °C and 1.00 atm, what is the temperature (in °C) of the
SO2? a. | -39 °C | b. | 29 °C | c. | 88 °C | d. | 249 °C | e. | 575 °C | | |
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7.
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The
pressure in a 20.0 L flask is 0.512 atm at 72 °C. How many moles of gas are in the flask? (R = 0.08206
L·atm/mol·K) a. | 0.0297 mol | b. | 0.142
mol | c. | 0.276
mol | d. | 0.362
mol | e. | 1.73
mol | | |
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8.
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A
50.0 L cylinder of Ar has a pressure of 137 atm at 25 °C. What mass of Ar is inside the cylinder? (R = 0.08206
L·atm/mol·K) a. | 0.143 g | b. | 4.48
g | c. | 918
g | d. | 2.80
x 102
g | e. | 1.12
x 104
g | | |
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9.
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What
volume is occupied by 8.50 g C2H2 at STP (standard temperature and pressure)?
(R = 0.08206 L·atm/mol·K) a. | 0.670 L | b. | 7.31
L | c. | 7.98
L | d. | 68.7
L | e. | 191
L | | |
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10.
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At
453 K and 755 mm Hg, what volume of N2 will react completely with 22.2 L H2 to
produce NH3?
N2(g)
+ 3 H2(g) → 2 NH3(g)
a. |
12.4
L | b. | 14.8
L | c. | 22.2
L | d. | 44.4
L | e. | 66.6
L | | |
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11.
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What
volume of O2, measured at 91.2 °C and 743 mm Hg, will be produced by the decomposition of 4.88 g
KClO3? (R = 0.08206 L·atm/mol·K)
2 KClO3(s) → 2 KCl(s) + 3 O2(g)
a. | 0.305
L | b. | 1.22
L | c. | 1.83
L | d. | 24.0
L | e. | 37.4
L | | |
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12.
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What
volume of O2(g), measured at 17.7 °C and 0.978 atm reacts with 15.1 g C4H10
to produce CO2(g) and H2O(l)? (R = 0.08206 L·atm/mol·K) a. | 2.51
L | b. | 6.34
L | c. | 23.5
L | d. | 41.2
L | e. | 239
L | | |
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13.
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Ammonia gas is synthesized according to the balanced equation
below.
N2(g) + 3 H2(g)
→ 2
NH3(g)
If 2.75 L N2 react with 7.75 L
H2, what is the theoretical yield (in liters) of NH3? Assume that the volumes
of reactants and products are measured at the same temperature and pressure. a. | 2.75
L | b. | 5.17
L | c. | 5.50
L | d. | 10.5
L | e. | 15.5
L | | |
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14.
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Hydrochloric acid reacts with zinc to produce hydrogen gas according to the reaction
below.
2 HCl(aq) + Zn(s)
→
ZnCl2(aq) + H2(g)
If 750.0 mL of 0.250 M HCl is combined with 5.98 g Zn, what volume of
dry hydrogen gas can be produced? Assume the temperature and pressure of the gas are 25 °C and 742 mm Hg,
respectively. (R = 0.08206 L·atm/mol·K) a. | 1.97
L | b. | 2.29
L | c. | 2.35
L | d. | 4.58
L | e. | 4.70
L | | |
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15.
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An
unknown gaseous hydrocarbon contains 85.63 % C. Its density is 0.426 g/L at 0.465 atm and 373 K. What
is the molecular formula of the gas? (R = 0.08206 L·atm/mol·K) a. | C2H4 | b. | C3H6 | c. | C4H8 | d. | C5H10 | e. | C6H12 | | |
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16.
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Carbon monoxide reacts with oxygen to form carbon dioxide.
2 CO(g) + O2(g) → 2 CO2(g)
In a 1.00 L flask, 2.40 atm of CO reacts with 4.50 atm of
O2. Assuming that the temperature remains constant, what is the final pressure in the
flask? a. | 1.20
atm | b. | 2.40
atm | c. | 3.30
atm | d. | 3.60
atm | e. | 5.70
atm | | |
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17.
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Place
the following gases in order of increasing average velocity at 325 K: Ar, Ne, N2, and
SO2. a. | Ar < Ne <
N2 < SO2 | b. | Ne < Ar < N2 <
SO2 | c. | N2 < SO2 < Ne <
Ar | d. | SO2
< Ar < N2 < Ne | e. | Ar = Ne = N2 =
SO2 | | |
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18.
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Carbon monoxide gas diffuses through a barrier at a rate of 0.480 mL/minute. If an
unknown gas diffuses through the same barrier at a rate of 0.277 mL/minute, what is the molar mass of
the gas? a. | 9.33
g/mol | b. | 21.3 g/mol | c. | 36.9
g/mol | d. | 44.01 g/mol | e. | 84.1
g/mol | | |
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19.
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How
long will it take 10.0 mL of Cl2 gas to effuse through a porous barrier if it has been
observed that 76.3 minutes are required for 10.0 mL of HCl gas to effuse through the same
barrier? a. | 54.7
min. | b. | 106
min. | c. | 148
min. | d. | 202
min. | e. | 289
min. | | |
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20.
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If a
gas effuses 1.618 times faster than Kr, what is its molar mass? a. | 18.02
g/mol | b. | 28.01 g/mol | c. | 32.01
g/mol | d. | 51.79 g/mol | e. | 65.88
g/mol | | |
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