CHEM 100 Sample Problems
SAMPLE Q
FOR CHAPTER 5
b. The average kinetic energy of a gas
1. Which of the following does not accurately
molecule increases as the temperature
describe a characteristic of gases?
a. Gas molecules can be "squeezed together" to
increases.
fit into a container.
c. Gas molecules are moving randomly in
b. The gas we exhale expands out continuously
various directions at one speed.
into the atmosphere.
d. The forces of attraction and repulsion
c. The vapors of two immiscible liquids (liquids
between gas molecules are proportional
that do not mix together, but form separate
to the size of the molecule.
layers) will mix completely.
e. Small amounts of energy are lost with
d. If a large container is filled with a small
each collision of gas molecules.
amount of gas, the gas will occupy only a
6. Arrange the following gaseous substances in
portion of the container.
order of decreasing average speed at 25C.
e. One must include the temperature, pressure,
argon, fluorine, carbon dioxide, oxygen,
volume occupied and number of moles or
helium
molecules to completely describe a gas.
a. carbon dioxide > argon > fluorine > oxygen >
2. Convert 699 torr to 1) atm, 2) mmHg and 3)
helium
kPa.
b. carbon dioxide > fluorine > argon > oxygen >
1) atm
2) mmHg
3) kPa
helium
Option 1: 5.31  105
93.2
c. helium > oxygen > fluorine > carbon dioxide >
5.31  105
Option 2: 0.920
699
93.2
argon
Option 3: 699
d. helium > oxygen > fluorine > argon > carbon
5.31  105
5.24  103
dioxide
Option 4: 6.90
6.995  105 7.08  104
e.
argon > oxygen > helium > carbon dioxide >
4
Option 5: 0.920
699
9.32  10
fluorine
a. Option 1
7.
If,
at constant temperature, the volume of a
b. Option 2
flask
equipped with a moveable piston is
c. Option 3
reduced
to 1/4 its original volume, what
d. Option 4
must
happen
to the pressure?
e. Option 5
a.
It
is
reduced
to
1/4 the original pressure.
3. One atmosphere of pressure is equal to 760
b. It is reduced to 1/8 the original pressure.
mmHg. This unit is used in the common
c. It is increased by 4 times the original pressure.
barometer and manometer. Determine
d. It is increased by 8 times the original pressure.
height (in mm) of a column of liquid
e. It remains the same as the original pressure.
bromine if the pressure is one atmosphere.
8. Suppose that in a known volume of He,
The densities of mercury and bromine are
there are 6.022  1023 molecules and 4.00 g
13.546 and 3.119 g/cm3, respectively.
at 1.00 atm and 0C. How many molecules
a. 4.34
b. 1.75  102
and how many grams of O are there under
c. 42.3
d. 760
the same conditions?
e. 3.30  103
a.
6.022  1023 molecules and 16.00 g
4. Based on temperature, there are four main
b.
1.00 molecules and 4.00 g
layers to our atmosphere. Which of the
c.
8(6.022  1023) molecules and 32.00 g
following is the correct name for the layer
d. 6.022  1023 molecules and 32.00 g
in which we live?
e. 6.022  1023 molecules and 4.00 g
a. stratosphere
9. Aluminum and oxygen react to form
b. mesosphere
aluminum oxide. How many L of oxygen at
c. ionosphere
23C and 1.4 atm of pressure are necessary
d. troposphere
e. thermosphere
to form 3.25 g of aluminum oxide?
5. Which of the following does the Kinetica. 0.55 b. 0.83 c. 1.3 d. 56 e. 6.5  10-2
Molecular Theory assume?
10. If 7.63 g of an unknown gas occupies 79.1
a. A gas is composed of atoms or
mL at 25.02C and 7.55 atm of pressure,
molecules whose size is proportional to
what is the molecular weight of that gas?
the distance between them. (Large
The value of R = 0.0821 L-atm/mole-K.
distance, large atom or molecule)
a. 31.2 b. 26.2 c. 312 d. 0.312 e. 3.21  10-3
11. Consider a gas mixture of 21% O2, 78% N2,
0.5% CO2 and trace amounts of Ar. Which
of the following represents the total
pressure exerted by the mixture?
a. P(O2) + P(N2) + P(CO2)
b. P(O2) + P(N2) + P(CO2) + P(Ar)
c. P(O2) + P(N2)
d. P(N2)
e. The pressure of the mixture is independent of
the partial pressures of the individual gases.
12. A mixture of H2(g) and Cl2(g) exerts a total
pressure of 2.50 atm. If the mole fraction
of H2 is 0.490, what is the partial pressure
(in atm) of H2?
a. 2.53 b. 0.396 c. 1.23 d. 2.50 e. 0.606
13. Solid potassium chlorate can be decomposed
to produce potassium chloride and oxygen
according to the following equation.
2KClO3(s)  2KCl(s) + 3O2(g)
How many grams of KClO3 are needed to
produce 752 mL of oxygen at 23C and 0.995
atm, if the oxygen is collected over water? The
vapor pressure of water at this temperature is
21.07 torr.
a. 3.77 b. 2.52 c. 2.44 d. 3.66 e. 0.0308
14. In the reaction: BF3 (g) + NH3 (g) ----> BF3
NH3 (s), how many liters of NH 3 at STP
would be required to react with 0.75 L of
BF3 at STP?
a. 0.75 L b. 1.5 L c. 14.7 L d. 200 mL
15. Acetylene, C2H2 (g), can be prepared by the
reaction of calcium carbide with water;
CaC2 (s) + 2H2O(l) -----> Ca(OH)2 (s) + C2H2 (g)
What volume of acetylene can be obtained from
125 g of calcium carbide and excess water at
25°C and 742 mm Hg?
a. 0.0657 L b. 5.04 L c. 5.39 mL d. 48.9 L
CHEM 100 SAMPLE TEST 3, CHAPTER 5
TEST FOR CHAPTER 5
1. A 10.0 L vessel contains 3.8 x 102 grams of
a. 0.88 L b. 1.59 L c. 1.92 L d. 3.50 L
8. A bubble of helium gas has a volume of 0.650
nitrogen gas. What is the pressure exerted by
this gas sample at 25°C?
mL near the bottom of a large aquarium where
a. 2.8 atm b. 33 atm c. 66 atm d. 78 atm
the pressure is 1.54 atm and the temperature is
2. A sample of gas is transferred from a 75.0 mL
12° C. Determine the bubble's volume upon
vessel to a 500.0 mL vessel. If the initial pressure
rising near the top where the conditions are 1.01
of the gas is 145 atm and if the temperature is
atm and 16° C.
A. 0.420 mL b. 0.432 mL c.0.978 mL d. 1.00
held constant, what is the pressure of this gas
mL
sample in the 500.0 mL container?
a. 21.8 atm b. 44.8 atm c. 57.6 atm d. 967 atm
9. Calculate the pressure (in atm) exerted by
3. Determine the density of neon at 82.5 mm Hg
58.2 g of steam (H 2 O vapor) confined to a
volume of 8.7 L at 100° C. a. 11 b. 55 c. 139
and 52.5° C.
a. 0.0820 g/L b. 0.508 g/L c. 12.2 g/L d. 62.2 g/L
d. 166
4. Given: 2KClO3 (s) ----> 2KCl(s) + 3O2 (g). If
10. A sample of nitrogen gas is collected in a
4.0 grams of potassium chlorate are
100.0 mL container at a pressure of 688 mm Hg
decomposed, how many liters of oxygen gas can
and a temperature of 565° C. How many grams
be collected at STP?
of nitrogen gas are present in this sample?
a. 0.0014 b. 1.1 c. 2.8 d. 89
a. 0.00195 g b. 0.0368 g c. 18.4 g d. 28.0 g
5. Convert a pressure of 0.0248 mm Hg to the
11. If 6.60 g of a gaseous compound occupy a
equivalent pressure in pascals (Pa);
volume of 1.20 L at 27° C and 0.967 atm, the
a. 3.31 Pa
b. 18.8 Pa
molar mass of the compound is;
c. 2.51 x 103 Pa d. 1.91 x 106 Pa
a. 109 g/mole b. 123 g/mole c. 140 g/mole
6. Air in a closed cylinder is heated from 25° C
d. 165 g/mole
12. A 0.271 gram sample of hydrazine, a liquid
to 36° C. If the initial pressure is 3.80 atm, what
is the final pressure?
rocket fuel, has a volume of 320 mL when
a. 2.64 atm b. 3.77 atm c. 3.94 atm d. 5.48 atm
vaporized at 748 mm Hg and 180° C. Calculate
7. A sample of argon gas at 30° C has a volume
the molar mass of hydrazine.
a. 4.20 g/mole b. 11.4 g/mole c. 12.7 g/mole
of 1.75 L. If the pressure and amount of gas
d. 32.0 g/mole
remain unchanged, determine the volume when
the temperature is increased to 60° C.
13. If a 0.300 L flask at 27°C and 1.00 atm
contains 0.975 g of vapor, the formula for the
vapor could be,
a. SO4 b. SO3 c. SO2 d. SO
14. In the reaction: BF3 (g) + NH3 (g) ----> BF3
NH3 (s), how many liters of NH 3 at STP would
be required to react with 0.75 L of BF3 at STP?
a. 0.75 L b. 1.5 L c. 14.7 L d. 200 mL
15. How many moles of zinc are needed to form
112 mL of H2 at 1.00 atm pressure and 0° C?
Zn(s) + 2H + (aq) -----> Zn2+ (aq) + H2 (g)
a. 0.00500 mole b. 0.0200 mole
c. 0.373 mole d. 3.37 mole
16. Acetylene, C2H2 (g), can be prepared by the
reaction of calcium carbide with water;
CaC2 (s) + 2H2O(l) -----> Ca(OH)2 (s) + C2H2 (g)
What volume of acetylene can be obtained from
125 g of calcium carbide and excess water at
25°C and 742 mm Hg?
a. 0.0657 L b. 5.04 L c. 5.39 mL d. 48.9 L
21. A gas occupies a volume of 1.50 L at 700
torr and 200 °C. Which mathematical
expression gives the correct volume at
400 torr and 100 °C?
22. For an ideal gas, which pairs of variables
are directly proportional to each other (if
all other factors remain constant)?
1. V, P 2. V, T 3. V, n
a. 1 and 2 only
b. 2 and 3 only
c. 1 only d. 2 only e. 1, 2, and 3
23. The temperature of a gas in a sealed
container changes from 20.0 °C to 40.0 °C.
If the volume remains constant, the
pressure will change from 740 torr to
a. 693 torr. b. 1480 torr.
c. 370 torr. d. 791 torr.
e. 760 torr.
24. What would be the number of moles (n) of
sample gas, if its, P = 760.00 torr, V = 1.000
L, and T = 1 C°?
a. 6.022 moles b. 1.000mole
c. 0.045 moles d. 760 moles
e. 274 moles
25. At STP, 3.56 L of a gas weighed 11.3 g. Its
molecular weight is
17. A gaseous mixture of 1.6 mole of helium,
0.34 mole of neon, and 1.2 mole of argon exerts
a pressure of 738 mm Hg in a particular
container. What is the partial pressure of neon
in this mixture?
a. 0.34 mm Hg b. 80 mm Hg
c. 251 mm Hg d. 738 mm Hg
18. If 4 moles of O2 and 4 moles of N2 occupy 12
liters at a pressure of 6 atm, the pressure due to
O2 in the container is,
a. 2 atm b. 3 atm c. 3.25 atm d. 4 atm
19. A mixture of nitrogen and argon gases is
confined to a container at a pressure of 747 mm
Hg. If the mole fraction of argon is 0.10 in this
mixture, its partial pressure is;
a.75 mm Hg b. 107 mm Hg
c. 297 mm Hg d. 672 mm Hg
20. What is the pressure of a gas mixture that
contains 1.0 g of hydrogen gas and 8.0 g of
argon in a 3.0 L container at 27° C?
a. 2.5 atm b. 3.7 atm c. 5.7 atm d. 73 atm
a. 3.17 g/mol. b. 11.3 g/mol.
c. 40.2 g/mol. d. 71.1 g/mol.
e. 79.7 g/mol.
26. Which of the following relates the volume of
gas to the temperature of gas?
a. Boyle's law b. Charles's law
c. Dalton's law d. Graham's law
e. Avogadro's hypothesis
27. What is the volume of 100g of CH4 (m.w.
=16.05 g/mol) at 25 °C and 1.00 atm
pressure?
a. 152 L
b. 100 L
c. 16.1 L d. 298 L
e. 1.00 L
28. The equation below represents the complete
combustion of ethane:
2C2H6 (g) + 7O2 (g) -----> 4CO2(g) + 6H2O(g)
At STP, what is the volume in liters of
carbon dioxide that can be obtained from
15.9 L of C2H6 and excess of oxygen?
( at STP volume of 1 mole of a gas = 22.4 L)
a. 15.9
b. 15.9 x 2 c. 15.9 x 3
d. 15.9 x 4/7 e. 15.9 x 7/4
29. Which of the following samples has the
most atoms?
a. 1.00 L of CH4 at STP
b. 1.00 L of C2H6 at STP
c. 1.00 L of SF6 at STP
d. 1.00 L of H2 at STP
e. 1.00 L of C3H8 at STP
30. The density of N2 gas at 0 oC and 2.00 atm
is
a. 28 g/L. b. 2.50 g/L. c. 1.25 g/L.
d. 0.625 g/L. e. 0.028 g/mL.
31. If d is the density of a gas, R the gas
constant, T the temperature, and P its
pressure, which of the following expressions
represents the molecular weight (m.w.) of a
gas?
a. d x P/RT
b. d x R/PT
c. d x RP/T
d. d x RT/P
e. 1/d x RT/P
32. At 27 °C and 275 torr, an unknown pure
gas has a density of 0.647 g/L. Which of the
following gases could be the unknown gas?
a. N2O(m.w.= 44.02) b. Ne (m.w. = 20.18)
c. C2H6 (m.w. = 30.08)d. CO (m.w. = 28.01)
e. F2
(m.w. = 38.00)
33. A sample of hydrogen is collected over
water at a total pressure of 648 torr at 22
°C. The vapor pressure of water at 22 °C is
19.8 torr. The partial pressure of the H2 is
a. 20 torr. b. 648 torr.
c. 760 torr. d. 628 torr.
e. 2 torr.
34. What is the partial pressure of oxygen in a
container that contains 2.0 mol of oxygen
and 3.0 mol of nitrogen when the total
pressure is 900 torr?
a. 130 torr b. 220 torr
c. 360 torr d. 440 torr
e. 670 torr
35. Three 1.0-L flasks are filled with H2, O2,
and Ne, respectively, at STP. Which of the
following statements is true ?
a. All the flasks have different number of gas
molecules.
b. The kinetic energy of the gas molecules is
the same in all the flasks.
c. The densities of all the gases are the same.
d. There are twice as many O2 and H2
molecules as Ne atoms.
e. The velocity of the gas molecules is the same
in all the flasks.
36. The barometric pressure at the eye of a
hurricane is 693 torr. What is this pressure
in atm?
(760 torr = 1 atm)
a. 8.9 atm b. 9.8 atm
c. 317 atm d. 0.912 atm
37. The density of NO2 gas at STP is
a. 46.0 g/L. b. 2.06 g/L.
c. 1.34 g/L. d. 1.81 g/L
38. A sample of 0.259 moles of H2 and 0.248
moles of O2 at 21.8°C in a 3.25 L cylinder
has a partial pressure due to oxygen of
a. 1.85 atm. b. 1.93 atm.
c. 3.78 atm. d. 59.1 atm.
39. The gas listed below which would
effuse most rapidly is
a. CCl4. b. CO2. c. N2. d. Ar.
40. Which of the following is not a gas at
everyday temperature and pressure?
a. chlorine b. hydrogen c. carbon d. methane
e. carbon dioxide
41. Based on temperature, there are four main
layers to our atmosphere. Which of the
following is the correct name for the layer
in which we live?
a.
stratosphere
b.
mesosphere
c.
ionosphere
d.
troposphere
e.
thermosphere
42. The following statements are a summary of
the Kinetic Molecular Theory. Which one is
incorrect?
a. All gases consist of atoms and molecules
moving randomly in all directions at various
speeds.
b. The average kinetic energy of gas molecules
increases as the temperature increases.
c. Gas molecules will eventually stop colliding
due to the energy lost in each collision.
d. There are no attractive or repulsive forces
between gas molecules.
e. The volume of a gas molecule is negligible
when compared to the space that separates
it from other gas molecules.
43. Which of the following correctly describes
the relationship between the pressure of a
gas and the volume of a gas at constant
temperature?
a. directly proportional
b. irreversibly proportional
c. indirectly proportional
d. as one increases the other increases
e. unrelated
44. When the pressure on a balloon is
decreased at constant temperature, what
happens to the gas inside?
a. The volume increases.
b. The molecules increase in rate of movement.
c. The volume decreases.
d. The collisions become more elastic.
e. The gas undergoes no changes.
45. If a 2.0-liter sample of gas experiences a
decrease in pressure from 1.74 atm to 0.555
atm at 25C, what is the resulting volume
(in L) at 25C?
a. 2.0 L b. 0.64 L c. 0.48 L d. 1.9 L e. 6.3 L
46. At 20C, sample of gas has a volume of 2.51
L at 795 torr. What is the new pressure (in
atm) if the volume is increased to 3.23 L at
the same temperature?
a. 618 b. 0.813 c. 1.35 d. 735 e. 0.0102
47. Which of the following is the mathematical
representation of Charles's Law?
a. V  T = constant
b. n  T = constant
c. V/T = constant
d. P/T = constant
e. PV = constant
48. Which of the following statements
summarizes Charles's Law?
a. The volume of a fixed amount of gas at a
constant pressure
is indirectly proportional to its absolute
temperature.
b. The pressure of a fixed amount of gas at
variable pressure
is directly proportional to its absolute
temperature.
c. The pressure of a variable amount of gas at
different pressures
is directly proportional to its absolute
temperature.
d. The volume of a fixed amount of gas at a
constant pressure
is directly proportional to its absolute
temperature.
e. The volume of a fixed amount of gas at a
constant temperature
is indirectly proportional to its pressure.
49. If, at constant pressure, the temperature of
a flask equipped with a moveable piston is
reduced to 1/2 its original Kelvin
temperature, what must be the new
volume?
a. two times the original volume
b. four times the original volume
c. 1/4 the original volume
d. 1/2 the original volume
e. the new volume is equal to the original volume
50. A balloon filled with gas is heated from
30.0C to 197.0C at constant pressure. If
the original volume of the balloon was 1.560
L, what is the volume (in L) of the gas after
heating?
a. 2.42 b. 10.2 c. 1.01 d. 0.238 e. 1.02
51. The volume of a gas in a flask is 250.0 mL at
23C and 1.00 atm of pressure. The gas is
transferred to a new flask with a volume of
1.200 L at the same pressure. Under these
new conditions, what is the temperature (in
C) of the gas?
a. 1.104  102 b. 1.421  103
c. 1.104  10-1 d. 1.421
e. 1.148  103 51. ANS: e. 1.148  103
52. Which of the following is the mathematical
representation of Avogadro's Law?
a. P/V = constant
b. V = constant  n
c. n = constant
d. 1/T = constant
e. n/V = constant
53. Which of the following is a summary of
Avogadro's Law?
a. At constant temperature and pressure, the
volume
of a gas is equal to the number of moles of the
gas.
b. At constant temperature and pressure, the
volume
of a gas is indirectly proportional to the number
of
moles of the gas.
c. At constant temperature and pressure, the
volume
of a gas is directly proportional to the number
of
moles of the gas.
d. At variable temperature and pressure, the
volume of a gas is
directly proportional to the number of moles of
the gas.
e. At constant temperature and pressure, the
volume of a gas is
not related to the number of moles of the gas.
54. What conditions are referred to as standard
temperature and pressure (STP) for gas
behavior?
a. 25C and 1 atm
b. 296 K and 760 torr
c. 0C and 1 atm
d. 0C and 1 mm Hg
e. 273C and 1 atm
55. How are the pressure and the Kelvin
temperature of a gas related?
a. They are exactly opposites.
b. They are directly proportional.
c. They are not related.
d. They are indirectly proportional.
e. Not enough information given to determine.
56. Derive the gas constant (in L-torr/mol-K)
for 1.000 mole of a gas occupying 22.4 L at
0.00C and 1.00 atm.
a. 8.21  10-2
b. 1.60  10-2
c. 62.4
d. 1.22  10-3
e. undefined due to division by zero
57. What is the pressure (in atm) exerted by a
4.00 mole sample of gas that occupies 2.5 L
at 34.00C? The value of R = 0.0821 Latm/mole-K.
a. 40.3
b. 4.47
c. 0.224
d. 2.48  10-2
e. 54.4
58. Calculate the number of moles of a gas that
occupy 7.3  103 mL at STP. The value of R
= 0.821 L-atm/mole-K.
a. 3.1
b. 3.3  102
c. 2.4 104
d. 0.33
e. undefined due to division by zero
59. If at 29C and 2.50 atm of pressure, a gas
occupies 5.99 L of space, what volume (in L)
will the same gas occupy at 19C and 1.20
atm of pressure?
a. 8.18
b. 2.04  10-4
c. 6.04  10-1
d. 20.0
e. 12.1
60. Suppose that at STP a gas occupies 10.2 L.
At what temperature (C) will the same gas
occupy 15000 mL at 1550 torr?
a. -273
b. 1.22  10-3
c. 6.22  105
d. 545
e. undefined due to division by zero
61. Suppose that a gas occupies 3.11 L at 795
mm Hg and 15.0C. What pressure (in atm)
will the same gas exert at 5.00 L and
31.0C?
a. 0.687
b. 2.61  103
c. 1.34
d. 1.02  103
e. 1.85  10-4
62. The following is the reaction that occurs in
automobile airbags:
2NaN3(s)  2Na(s) + 3N2(g)
How many grams of sodium azide (NaN3)
are required to produce 38.00 L of N2 at
20.0C and 775 mm Hg?
a. 5.31  104
b. 104
c. 7.77  105
d. 1.16  106
e. 69.8
63. What volume (in L) of oxygen at 25C and
1.50 atm of pressure is required for the
complete combustion of 25.0 g of hexane?
The value of R = 0.0821 L-atm/mol-K.
2C6H14 + 19O2  12CO2 + 14H2O
a. 4.73
b. 0.397
c. 45.0
d. 407
e. 34.2
64. Iron and chlorine react to form iron(III)
chloride. At what Kelvin temperature
would 5.68 L of chlorine at 2.3 atm need to
be to completely react with 4.25 g of iron?
a. 2.1  103
b. 1.4  103
c. 3.1  103
d. 3.7  101
e. 2.5  101
65. Determine the volume (in L) of Cl2(g)
required to carry out the following reaction
at 794 torr and 625C using 15.0 g of Fe.
The value of R = 0.0821 L-atm/mol-K.
2Fe(s) + 3Cl2(g)  2FeCl3(s)
a. 1.06  103 b. 0.0374 c. 19.8
d. 28.4 e. 19.0
66. What is the molecular weight of 3.7 g of an
unknown gas that occupies 450 mL at
20.0C and 2.0 atm? The value of R =
0.0821 L-atm/mole-K.
a. 3.7  10-2
b. 98.9
c. 5.5  103
d. 9.9  10-3
e. 6.8
67. How many liters does 6.672 g of nitrogen
dioxide occupy at 30.1C and 2.1 atm of
pressure? The value of R = 0.0821 Latm/mole-K.
a. 0.17 b. 1.7 c. 7.9 d. 79 e. 0.15
68. The density of an unknown gas is 0.350 g/L
at 40.00C. If the gas occupies 30.3 L and
has a pressure of 2.22 atm at 40.00C, what
is the molecular weight of the gas? The
value of R = 0.0821 L-atm/mole-K.
a. 4.05 b. 0.134 c. 0.382 d. 0.518 e. 0.0171
69. What is the density (in g/L) of methane at
25C and 1.2 atm of pressure? The value of
R = 0.0821 L-atm/mole-K.
a. 4.90  10-2 b. 9.9 c. 6.21  103
d. 1.20 e. 0.785
70. A mixture of He, Ne and Ar has a total
pressure of 1.6 atm and is found to contain
0.55 mol He, 0.94 mol Ne and 0.35 mol Ar.
What is the partial pressure (in atm) of each
gas?
He
Ne
Ar
Option 1:
0.88
1.50
0.56
Option 2:
0.48
0.82
0.30
Option 3:
5.4
3.1
8.4
Option 4:
2.9
1.7
2.9
Option 5:
0.19
0.32
0.12
a. Option 1
b. Option 2
c. Option 3
d. Option 4
e. Option 5
71. A 25.0 L flask contains 3.50 g of sulfur
trioxide, 2.45 g of carbon monoxide, and
3.99 g of argon all at 35C. What is the
pressure (in atm) in the flask?
a. 0.0442 b. 0.234 c. 10.1
d. 1.14
e. 1.17
72. Suppose that 1.00 gram of each of the three
inert gases, Ne, Ar, Kr, are combined in a
1.00-L flask at 25.0C. Determine the
partial pressures of each of the three gases
in the flask in torr.
Ne
Ar
Kr
Option 1:
1.21
0.608
0.292
Option 2:
923
465
222
Option 3:
923
465
222
Option 4:
1.86  104
1.86  104
1.86  104
Option 5:
24.4
24.4
24.4
a. Option 1
b. Option 2
c. Option 3
d. Option 4
e. Option 5
73. Zinc metal reacts with hydrochloric acid to
produce zinc chloride and hydrogen gas.
How many mL of hydrogen are produced at
27C and 1.35 atm if 4.66 g of zinc are
reacted with excess hydrochloric acid and
collected over water? The vapor pressure of
water at this temperature is 26.74 torr.
a. 1.34  103 b. 650 c. 1.30  103
d. 3.28  10-2 e. 667
74. Under what conditions do real gases most
closely approximate the behavior of ideal
gases?
a. standard temperature and pressure
b. low pressure and high temperature
c. low pressure and low temperature
d. high pressure and high temperature
75. Which two assumptions of the KineticMolecular Theory need to be altered to
account for the behavior of real gases?
I.
gas molecules undergo perfectly elastic collision
II. gas molecules have no volume
III. gas molecules move in random motion
IV. gas molecules undergo no attractive or repulsive
force toward one another
a. I and II
b. I and III
c. II and III
d. II and IV
e. III and IV
76. Which of the following describes one way in
which a real gas differs from an ideal gas?
a. Real gases occupy no space.
b. Real gases have no kinetic energy.
c. Real gases have attractions for one another.
d. Real gases do not move in random motion.
e. Real gases exist only at STP.
77. In which layer of the atmosphere is ozone
formed?
a. stratosphere
Total
b. mesosphere
2.11
c. ionosphere
923
d.  troposphere
1.61
103
e.
thermosphere
5.58  103
78. What net product results from the reaction
73.2
of ozone with CFCs?
a. oxygen molecules
b. chlorine molecules
c. oxygen radicals
d. water
e. hydrogen
79. Which of the following is not caused by
atmospheric pollutants?
a. decreased lung capacity
b. a stronger immune system
c.
d.
e.
80.
harm to vegetation
coughing
burning eyes
Which of the following is not an air
pollutant?
a. SO2 b. Pb c. NO2 d. He e. NO
Answer Key
1.> b. 33 atm
2. > a. 21.8 atm
3. > a. 0.0820 g/L
4. > b. 1.1
5. > a. 3.31 Pa
6. > c. 3.94 atm
7. > c. 1.92 L
8. > d. 1.00 mL
9. > a. 11
10.> b. 0.0368 g
11.> c. 140 g/mole
12.> d. 32.0 g/mole
13.> b. SO3
14.> a. 0.75 L
15.> a.. 0.00500 mole
16.> d. 48.9 L
17.> b. 80 mm Hg
18.> b. 3 atm
19.> a.75 mm Hg
20.> c. 5.7 atm
21.>d 1.50 x <<<EQUATION>>>
22.>b 2 and 3 only
23.>d 791 torr.
24.>c 0.045 moles
25.>d 71.1 g/mol.
26.>b Charles's law
27.>a 152 L
28.>b 15.9 x 2
29>e 1.00 L of C3H8 at STP
30.>b 2.50 g/L.
31.>d d x RT/P
32.>a N2O (m.w. = 44.02)
33.>d 628 torr.
34.>c 360 torr
35.>b The kinetic energy of the gas molecules is
the same in all the flasks.
36.> d 0.912 atm
37.> b 2.06 g/L.
38.> a 1.85 atm.
39.> d. Ar.
40. > c. carbon
41. > d. troposphere
42. > c. Gas molecules will eventually stop
colliding due to the energy lost in each collision.
43. > c. indirectly proportional
44. > a. The volume increases.
45. > e. 6.3 L
46. > b. 0.813
47. >:c. V/T = constant
48. > d. The volume of a fixed amount of gas at a
constant pressure is directly proportional to its
absolute temperature.
49. > d. 1/2 the original volume
50. > a. 2.42
51. > e. 1.148  103
52. > b. V = constant  n
53. > c. At constant temperature and pressure, the
volume of a gas is directly proportional to the
number of moles of the gas.
54. > c. 0C and 1 atm
55. > b. They are directly proportional.
56. > c. 62.4
57. > a. 40.3
58. > d. 0.33
59. > e. 12.1
60. > d. 545
61. > a. 0.687
62. > e. 69.8
63. > c. 45.0
64. > b. 1.4  103
65. > d. 28.4
66. > b. 98.9
67. > b. 1.7
68. > a. 4.05
69. > e. 0.785
70. > b. Option 2
71. > b. 0.234
72. > c. Option 3
73. > a. 1.34  103
74. > b. low pressure and high temperature
75. > d. II and IV
76. > c. Real gases have attractions for one another.
77. > a. stratosphere
78. > a. oxygen molecules
79. > b. a stronger immune system
80. > d.. He