A)
The packing is done in a way that minimizes repulsions among ions with like
charges.
B)
The packing arrangement maximizes electrostatic attractions among oppositely
charged ions.
C)
For spheres of a given diameter, tetrahedral holes are larger than octahedral holes.
D)
Trigonal holes are so small that they are never occupied.
E)
None of these.
74. An atom in an octahedral hole is surrounded by ____ atoms.
A)
2
B)
3
C)
4
D)
6
E)
8
75. A salt, MY, crystallizes in a body-centered cubic structure with a Y– anion at each cube
corner and an M+ cation at the cube center. Assuming that the Y– anions touch each other
and the M+ cation at the center, and the radius of Y– is 1.50 102 pm, the radius of M+ is:
A)
62.0 pm
B)
110. pm
C)
124 pm
D)
220. pm
E)
none of these
76. Sodium oxide (Na2O) crystallizes in a structure in which the O2– ions are in a face-centered
cubic lattice and the Na+ ions are in tetrahedral holes. The number of Na+ ions in the unit
cell is:
A)
2
B)
4
C)
6
D)
8
E)
none of these
77. A certain metal fluoride crystallizes in such a way that the fluoride ions occupy simple cubic
lattice sites, while the metal atoms occupy the body centers of half the cubes. The formula
for the metal fluoride is:
A)
MF2
B)
M2F
C)
MF
D)
MF8
E)
none of these
78. Which of the following is most likely to be a solid at room temperature?
A)
Na2S
B)
HF
C)
NH3
D)
N2
E)
H2O
79. On the basis of your knowledge of bonding in liquids and solids, which of the following has
the lowest melting temperature?
A)
NaCl
B)
Na
C)
Cl2
D)
SiO2
E)
More information is needed.
80. Which of the following substances would you expect to have the lowest boiling point?
A)
diamond
B)
methane, CH4
C)
sodium nitrate, NaNO3
D)
glycerine, C3H5(OH)3
E)
copper
81. On a relative basis, the weaker the intermolecular forces in a substance,
A)
the greater its heat of vaporization
B)
the more it deviates from ideal gas behavior
C)
the greater its vapor pressure at a particular temperature
D)
the higher its melting point
E)
none of these
82. At normal atmospheric pressure and a temperature of 0°C, which phase(s) of H2O can exist?
A)
ice and water
B)
ice and water vapor
C)
water only
D)
water vapor only
E)
ice only
83. The process of condensation happens when which of the following occurs?
A)
A solid becomes a liquid.
B)
A liquid becomes a solid.
C)
A gas becomes a liquid.
D)
A liquid becomes a gas.
E)
A gas becomes a solid.
84. Which of the following processes must exist in equilibrium with the evaporation process
when a measurement of vapor pressure is made?
A)
fusion
B)
vaporization
C)
sublimation
D)
boiling
E)
condensation
85. Assume 12,500 J of energy is added to 2.0 moles (36 grams) of H2O as an ice sample
at 0°C. The molar heat of fusion is 6.02 kJ/mol. The specific heat of liquid water is
4.18 J/g °C. The molar heat of vaporization is 40.6 kJ/mol. The resulting sample contains
which of the following?
A)
only ice
B)
ice and water
C)
only water
D)
water and water vapor
E)
only water vapor
86. You are given the following boiling point data. Which one of the liquids would you expect
to have the highest vapor pressure at room temperature?
A)
water, H2O 100°C
B)
methanol, CH3OH 64.96°C
C)
ethanol, CH3CH2OH 78.5°C
D)
diethyl ether, CH3OH2–O–CH2CH3 34.5°C
E)
ethylene glycol, HO–CH2–CH2–OH 198°C
87. Given below are the temperatures at which two different liquid compounds with the same
empirical formula have a vapor pressure of 400 torr.
Compound
T (°C)
dimethyl ether, CH3–O–CH3
–37.8
ethanol, CH3CH2OH
63.5
Which of the following statements (a–d) is false?
A)
Increasing the temperature will increase the vapor pressure of both liquids.
B)
Intermolecular attractive forces are stronger in (liquid) ethanol than in (liquid)
dimethyl ether.
C)
The normal boiling point of dimethyl ether will be higher than the normal boiling
point of ethanol.
D)
The reason that the temperature at which the vapor pressure is 400 torr is higher
for ethanol (than for dimethyl ether) is that there is strong hydrogen bonding in
ethanol.
E)
None of these is false.
88. Given the graph below, what is the boiling point of chloroform at standard pressure?
A)
77°C
B)
34°C
C)
98°C
D)
60°C
E)
The graph does not give that information.
89. A liquid placed in a closed container will evaporate until equilibrium is reached. At
equilibrium, which of the statements (A-D) is false?
A)
The partial pressure exerted by the vapor molecules is called the vapor pressure of
the liquid.
B)
Liquid molecules are still evaporating.
C)
The number of vapor molecules remains essentially constant.
D)
The boundary (meniscus) between liquid and vapor disappears.
E)
All of these are true.
90. Which one of the following decreases as the strength of the attractive intermolecular forces
increases?
A)
the heat of vaporization
B)
the normal boiling temperature
C)
the extent of deviations from the ideal gas law
D)
the sublimation temperature of a solid
E)
the vapor pressure of a liquid
91. Knowing that Hvap for water is 40.7 kJ/mol, calculate Pvap of water at 58°C.
A)
5.3 torr
B)
456 torr
C)
14.8 torr
D)
759 torr
E)
144 torr
92. Water sits in an open beaker. Assuming constant temperature and pressure, the rate of
evaporation decreases as the water evaporates.
93. Water sits in an open beaker. Assuming constant temperature and pressure, the vapor
pressure of the water decreases as the water evaporates.
94. Generally the vapor pressure of a liquid is related to:
I.
the amount of liquid
II.
atmospheric pressure
III.
temperature
IV.
intermolecular forces
A)
I, III
B)
II, III, IV
C)
I, III, IV
D)
III, IV
E)
I, II, III, IV
95. In which of the following processes will energy be evolved as heat?
A)
sublimation
B)
crystallization
C)
vaporization
D)
melting
E)
none of these
96. When one mole of benzene is vaporized at a constant pressure of 1.00 atm and at its boiling
point of 353.0 K, 30.56 kJ of energy (heat) is absorbed and the volume change is +28.90 L.
What is E for this process? (1 L·atm = 101.3 J)
A)
30.56 kJ
B)
59.46 kJ
C)
33.49 kJ
D)
1.66 kJ
E)
27.63 kJ
97. When one mole of benzene is vaporized at a constant pressure of 1.00 atm and at its boiling
point of 353.0 K, 30.53 kJ of energy (heat) is absorbed and the volume change is +28.90 L.
What is H for this process? (1 L·atm = 101.3 J)
A)
27.60 kJ
B)
33.46 kJ
C)
1.63 kJ
D)
30.53 kJ
E)
59.43 kJ
98. The normal boiling point of liquid X is less than that of Y, which is less than that of Z.
Which of the following is the correct order of increasing vapor pressure of the three liquids
at STP?
A)
X, Y, Z
B)
Z, Y, X
C)
Y, X, Z
D)
X, Z, Y
E)
Y, Z, X
99. The vapor pressure of water at 100.0°C is
A)
85 torr
B)
760 torr
C)
175 torr
D)
1 torr
E)
More information is needed.
100. How much energy is needed to convert 54.1 grams of ice at 0.00°C to water at 75.0°C?
specific heat (ice) = 2.10 J/g°C
specific heat (water) = 4.18 J/g°C
heat of fusion = 333 J/g
heat of vaporization = 2258 J/g
A)
17.0 kJ
B)
1.94 kJ
C)
26.5 kJ
D)
35.0 kJ
E)
139 kJ
101. The vapor pressure of water at 80°C is
A)
0.48 atm
B)
1.00 atm
C)
1.20 atm
D)
2.00 atm
E)
5.00 atm
102. Which of the following has the highest boiling point?
A)
chalk (calcium carbonate)
B)
ice (water)
C)
window cleaner (ammonia)
D)
motor oil (hydrocarbon chains)
E)
helium gas inside a party balloon
103. How many grams of ice would be melted by the energy obtained as 16.2 g of steam is
condensed at 100°C and cooled to 0°C?
specific heat (ice) = 2.10 J/g°C
specific heat (water) = 4.18 J/g°C
heat of fusion = 333 J/g
heat of vaporization = 2258 J/g
A)
43.4 kg
B)
36.6 kg
C)
130 g
D)
6.77 kg
E)
20 g
104. The heat of combustion of bituminous coal is 2.50 104 J/g. What quantity of the coal is
required to produce the energy to convert 106.9 pounds of ice at 0.00°C to steam at 100.°C?
specific heat (ice) = 2.10 J/g°C
specific heat (water) = 4.18 J/g°C
heat of fusion = 333 J/g
heat of vaporization = 2258 J/g
A)
5.84 kg
B)
0.646 kg
C)
0.811 kg
D)
4.38 kg
E)
1.46 kg
105. The process of changing from a vapor to a liquid is vaporization.
106. A certain substance, X, has a triple-point temperature of 20°C at a pressure of 2.0 atm.
Which one of the statements (A-D) cannot possibly be true?
A)
X can exist as a liquid above 20°C.
B)
X can exist as a solid above 20°C.
C)
Liquid X can exist as a stable phase at 25°C, 1 atm.
D)
Both liquid and solid X have the same vapor pressure at 20°C.
E)
All of the statements (A-D) could be true.
107. Which statement regarding water is true?
A)
Energy must be given off in order to break down the crystal lattice of ice to a
liquid.
B)
Hydrogen bonds are stronger than covalent bonds.
C)
Liquid water is less dense than solid water.
D)
Only covalent bonds are broken when ice melts.
E)
All of the statements (A–D) are false.
108. The triple point of iodine is at 90 torr and 115°C. This means that liquid I2
A)
is more dense than I2(s)
B)
cannot exist above 115°C
C)
cannot exist at 1 atmosphere pressure
D)
cannot have a vapor pressure less than 90 torr
E)
can exist at pressure of 10 torr
109. The triple point of CO2 is at 5.2 atm and –57°C. Under atmospheric conditions present in a
typical Boulder, Colorado, laboratory (P = 630 torr, T = 23°C), solid CO2 will:
A)
remain solid
B)
boil
C)
melt
D)
sublime
E)
none of these
110. Choose the correct statement about the diagram below.
A)
The diagram is qualitatively correct for water.
B)
The diagram shows that the melting point of the solid increases with increasing
pressure.
C)
The diagram shows the triple point above 1 atm pressure.
D)
The diagram could represent the phase diagram of CO2.
E)
None of the above statements is correct.
111. Below is a phase diagram for compound Q. You wish to purify a sample of Q that was
collected at P = 1.0 atm and T = 100 K by subliming it. In order to sublime the sample, you
should:
A)
Increase P to 1.5 atm and then increase T to 300 K.
B)
Increase T to 300 K, keeping P = 1.0 atm.
C)
Lower P to 0.5 atm and then increase T to 200 K.
D)
Increase T to 300 K and then lower P to 0.5 atm.
E)
Abandon the attempt to sublime Q.
112. Shown below is a phase diagram for compound Y. At 25°C and 1 atm Y will exist as a:
A)
solid
B)
liquid
C)
gas
D)
gas/liquid at equilibrium
E)
gas/solid at equilibrium
113. Below is a phase diagram for compound Y. The normal boiling point of Y is most likely:
A)
21°C
B)
47°C
C)
63°C
D)
18°C
E)
0°C
114. Shown below is a phase diagram for compound Y.
How will the melting point of Y change with increased pressure?
A)
increase
B)
decrease
C)
remain the same
D)
not enough information given
E)
increase and then decrease
115. Based on the phase diagram shown below, which of the following statements are correct?
I.
Sublimation occurs at a point in the transformation that occurs along a straight line
from point A to point F.
II.
C and E represent points where the gas and liquid phases are in equilibrium.
III.
Hvap can be measured at point B.
IV.
Molecules at point D have a greater average kinetic energy than those at point F.
V.
The temperature at point E is called the critical temperature of the compound.
A)
II, V
B)
I, III, IV
C)
I, II, III
D)
II, IV, V
E)
I, II, IV
116. A certain substance has the phase diagram shown below. At which of the following values
of T and P is the substance a pure liquid?
A)
T = 8°C, P = 1 atm
B)
T = 10°C, P = 0.5 atm
C)
T = 70°C, P = 1.2 atm
D)
T = 80°C, P = 1 atm
E)
T = 10°C, P = 1 atm
117. A sample consisting of CO2(g) and CO2(s) at equilibrium at –78°C and 1 atm pressure is
heated to –30°C and the pressure is increased to 8 atm. Based on the phase diagram below,
what will happen?
A)
At equilibrium, only CO2(g) will be present.
B)
All of the CO2 will be converted to CO2(l).
C)
At equilibrium, CO2(g) and CO2(l) will be present.
D)
The melting point of the CO2(s) will decrease.
E)
None of these.
118. Given the phase diagram below, which of the following statements (A–D) is false?
A)
The solid has a higher density than the liquid.
B)
At some (constant) temperature, the gaseous substance can be compressed into a
solid and then into a liquid in this order.
C)
When phase A is compressed at constant temperature at point X, no change is
observed.
D)
When heated at 1 atm, this substance will first melt, then boil.
E)
None of the above statements is false.
119. The density of the solid phase of a substance is 0.90 g/cm3 and the density of the liquid
phase is 1.0 g/cm3. A large increase in pressure will
A)
lower the freezing point
B)
raise the freezing point
C)
lower the boiling point
D)
raise the triple point
E)
lower the triple point
120. Make a sketch to show the hydrogen bonding between two acetic acid molecules
(HC2H3O2).
121. If you have 10.0 moles of BH3 and 5.0 moles of HF, which amount exhibits the most
hydrogen bonding? Explain.
Check question
See Sec. 10.1 of Zumdahl, Chemistry.
PTS: 1 DIF: Easy REF: 10.1
KEY: Chemistry | general chemistry | phases | liquid | intermolecular forces
MSC: Conceptual
122. The particularly strong dipole-dipole interaction between hydrogen in one molecule and
nitrogen in another molecule is known as a __________.
123. The relatively weak forces that exist among noble gas atoms are __________.
124. The meniscus of mercury curves downward at the edges. Explain using the concepts of
cohesion and adhesion.
125. The resistance of a liquid to an increase in its surface area is the __________ of the liquid.
126. The structures of crystalline solids are most commonly determined by __________.
127. In a(n) __________ alloy some of the host metal atoms are replaced by other metal atoms of
similar size.
128. Iodine moves directly from solid to gas in a process called __________.
129. Explain why water boils at a lower temperature up in the mountains versus at sea level.
Include at least one microscopic drawing in your explanation.
130. 100. g of ice at 0°C is added to 300.0 g of water at 60°C. Assuming no transfer of heat to the
surroundings, what is the temperature of the liquid water after all the ice has melted and
equilibrium is reached?
specific heat (ice) = 2.10 J/g°C
specific heat (water) = 4.18 J/g°C
heat of fusion = 333 J/g
heat of vaporization = 2258 J/g
