Gases and
Kinetic-Molecular Theory Copyright
D. Herrick
20 Questions from past exams.
Practice for speed. Aim
for 2 minutes per problem.
Constants: Avogadro's number: NA = 6.0221 × 1023
/ mole
Universal gas constant: R
= 0.08206 L-atm/mol-K = 8.314
J/mol-K
Pressure:
1 atm = 760 mmHg = 760 torr
Normal freezing
point of water: 0.00ºC =
273.15K
Normal boiling
point of water: 100.00ºC =
373.15K
Triple point of
water: 0.01ºC = 273.16K
1.
The
initial (V1) and final (V2)
volumes of a gas sample satisfy ____ when the absolute
temperature is doubled and the pressure is tripled.
A)
V2
= 0.667 V1
D)
V2
= 1.00 V1
B)
V2
= 1.50 V1
E)
V2
= 2.67 V1
C)
V2
= 0.38 V1
F)
V2
= 6.00 V1
2.
Convert
0.50 atm to mmHg.
A) 760
B)
1520
C)
380
D)
547
E)
670
3.
According
to Boyle a gas sample at a fixed temperature satisfies
A)
V/P2
is constant
D)
V/P
is constant
B)
PV
is constant
E)
V
and P are constant
C)
P/V2
is constant
F)
PV2
is constant
4.
The
initial (V1) and final (V2)
volumes of a gas satisfy ______ when the absolute temperature is doubled and the pressure is reduced by
50%.
A)
V2
= 0.25 V1
D)
V2
= 4.00 V1
B)
V2
= 0.50 V1
E)
V2
= 2.00 V1
C)
V2
= 1.00 V1
F)
V2
= 0.75 V1
5.
The
volume of 2 moles of an ideal gas at 200°C and 1500
mmHg is
A) 27.1
L
B) 30.0
L
C)
32.6 L
D) 44.8
L
E)
39.3
6.
A
2.00 L cylinder containing 84.0 g of nitrogen gas
can hold pressures up to 100 atm. What is the
highest temperature the gas can be heated before the
cylinder explodes?
A)
683°C
B)
420°C
C)
540°C
D)
722°C
E)
492°C
7.
The
temperature of a gas in a sealed container changes from
20°C to 40°C. If the volume remains constant,
the pressure (mmHg) will change from 740 mmHg to
A)
790
B)
812
C)
722
D)
1480
E)
760
solid
liquid
gas
8.
A
sample of H2(g) has a volume of 4 L,
and a sample of O2(g) at the same temperature
andpressure has a volume of 2 L. Which statement is correct?
A)
The
number of H2
molecules equals the number of O2
molecules.
B)
There
are twice as many O2
molecules as
H2
molecules.
C)
There
are twice as many
H2
molecules as O2
molecules.
D)
The
mass of the O2
gas is twice the mass of the
H2
gas.
E)
The
mass of the H2 gas is twice the mass of
the O2
gas.
9.
Which
gas has the highest density (g/L) at 0.6 atm, 380°C?
A) C6H6
B)
Xe
C)
SO2
D)
Br2
E)
CCl4
10.
A gas mixture of 2 moles of hydrogen and 1 mole of
oxygen has a pressure of 810 mmHg.What is the partial pressure of hydrogen in
mmHg?
A)
810
B) 540
C)
405
D)
270
E)
420
11.
What mass of phosphorous will react
with 52.1 L of O2 gas at STP by
P4(s) + 5 O2(g)
P4O10(s)
A) 57.6
g
B)
48.5 g
C)
64.1 g
D)
50.6 g
E)
66.3 g
12.
Analysis of a mixture of O2
and N2 gases at 760 torr shows the partial
pressure of O2 is 292 torr. What is the
partial pressure of N2 in mmHg?
A) 234
B)
584
C) 468
D)
292
E) 380
13.
Determine the volume relationship when
a sample of an ideal gas is taken from T1 =
450K and P1 = 300 mmHgto T2 = 900K and P2 = 900 mmHg.
A)
V2
= 0.33 V1
D)
V2
= 1.33 V1
B)
V2
= 1.67 V1
E)
V2
= 0.75 V1
C)
V2
= 1.50 V1
F)
V2
= 0.67 V1
14.
What
volume of oxygen gas at STP will react with 30 L of
hydrogen gas at STP?
2 H2(g) + O2(g)
2H2O(g)
A)
30 L
B)
33 L
C)
0.45 L
D)
60 L
E) 15 L
15.
A
product gas mixture from the reaction
NH4NO3(s)
N2O(g) + 2H2O(g)
has a pressure of 786 mmHg.
What is the partial pressure (mmHg) of N2O
in the mixture?
A)
128
B)
393
C) 262
D)
480
E)
534
16.
The
density (g/L) of all ideal gases at the same temperature
and pressure is directly proportional to the _______ of
the gas.
A)
molecular
weight
B)
square
root of the molecular weight
C)
reciprocal
of the molecular weight.
D)
reciprocal
of the square root of the molecular weight.
E)
square
of the molecular weight.
17.
According
to the kinetic theory of gases the absolute temperature
of a gas is directly proportional to the ______ of the
gas molecules.
A)
average speed
B)
reciprocal of the average kinetic energy
C)
square root of the kinetic energy
D)
average kinetic energy
E)
most probable speed
18.
Properties
of a real gas are most likely to deviate from
those predicted for an ideal gas when
A)
P
is low and T is low
B)
P
is high and T is low
C)
P
is high and T is high
D)
P
is low and T is high
19.
Which
distribution for a gas at two different temperatures
represents the higher average kinetic
energy?
A)
curve
1 (higher temperature)
B)
curve
1 (lower temperature)
C)
curve
2 (higher temperature)
D)
curve
2 (lower temperature)
E)
the
average kinetic energy is the same for both curves
20.
What do the constants "a"
and "b" represent in the van der Waals
equation of state for one mole of gas?
(P + a/V2) (V-b) = RT
A)
a
= attractive forces between molecules; b = attractive
forces between molecules
B)
a
= finite size of molecules; b = attractive forces
between molecules
C)
a
= finite size of molecules; b = finite size of molecules
D)
a
= attractive forces between molecules; b = finite size
of molecules
P4O10(s)
