General Chemistry: Atoms First, 2e (McMurry and Fay)
Chapter 10 Liquids, Solids, and Phase Changes
10.1 Multiple Choice Questions
1) The bonds in the polyatomic ion CO32– are classified as
A) ionic.
B) metallic.
C) nonpolar covalent.
D) polar covalent.
2) Which covalent bond is the most polar?
A) N-F
B) C-F
C) Cl-F
D) F-F
3) Which has a dipole moment?
A) CO2
B) CO32–
C) SO2
D) SO42–
4) Which of the following molecules does not have a dipole moment?
A) CH2=CH2
B) NH3
C) CH3NH2
D) HCl
5) Which of the following should have the largest dipole moment?
A) H2(g)
B) CO2(g)
C) KCl(g)
D) CH3F(g)
6) The dipole moment of ClF is 0.88 D, and its bond length is 163 pm. What is the percent ionic
character of the Cl-F bond?
A) 0.54%
B) 7.8%
C) 11%
D) 25%
7) The dipole moment of BrF is 1.29 D, and its bond length is 178 pm. What is the percent ionic
character of the Br-F bond?
A) 3.9%
B) 8.5%
C) 15%
D) 33%
8) AgCl is found to have 78.1% ionic character, and its gas phase dipole moment is 11.5 D. What
is the distance between the Ag and Cl atoms in gaseous AgCl?
A) 9.19 x 10-10 pm
B) 14.7 pm
C) 307 pm
D) 903 pm
9) Which has the smallest dipole-dipole forces?
A) CH3F
B) HCl
C) N2
D) CO
10) Which of the following does not exhibit hydrogen bonding?
A)
B)
C) HF
D) HO COH
11) Which of the following compounds exhibits hydrogen bonding?
A) CH3Cl
B) HI
C) H3C-O-CH3
D) NH3
12) Which of the following exhibits hydrogen bonding?
A) OH
B) O
C)
D) HCN
13) Which of the following exhibits ion-dipole forces?
A) NaCl(s)
B) NaCl(aq)
C) Na(s)
D) Cl2(g)
14) Which is expected to have the largest dispersion forces?
A) C2H6
B) C8H18
C) N2
D) CO2
15) Which substance in each of the following pairs is expected to have the larger dispersion
forces?
A) Br2 in set I and n-butane in set II
B) Br2 in set I and isobutane in set II
C) I2 in set I and n-butane in set II
D) I2 in set I and isobutane in set II
16) Which of the following compounds exhibits only dipole-dipole intermolecular interactions?
A) N2
B) HBr
C) CO2
D) H2O
17) In liquid methanol,
CH3OH
which intermolecular forces are present?
A) Dispersion, hydrogen bonding and dipole-dipole forces are present.
B) Only dipole-dipole and ion-dipole forces are present.
C) Only dispersion and dipole-dipole forces are present.
D) Only hydrogen bonding forces are present.
18) When a narrow diameter glass tube is inserted into a body of water, water rises in the tube
and its surface inside is concave upwards. Which statement, concerning the strength of the
intermolecular forces between glass and water molecules compared to those between water
molecules, is accurate?
A) The forces of attraction between the glass and water are weaker than those in water.
B) The forces of attraction between the glass and water are stronger than those in water.
C) The forces of attraction between the glass and water are the same as those in water.
D) Intermolecular forces are irrelevant to this situation.
19) Which of the intermolecular forces is the most important contributor to the high surface
tension shown by water?
A) dipole-dipole forces
B) dispersion forces
C) hydrogen bonding
D) ion-dipole forces
20) Which of the following is most likely to have the highest viscosity at 25°C?
A) C4H10
B) HOCH2CH2OH
C) C8H18
D) C2H5NH2
21) Which is expected to have the highest surface tension at 25°?
A) C5H12
B) C6H6
C) C2H5OH
D) C3H5(OH)3
22) The magnitude of the heats of vaporization, fusion and sublimation of a substance reflect the
A) density of the substance.
B) magnitudes of the boiling and melting points of the substance.
C) strength of the covalent bonds between atoms in each molecule of the substance.
D) strength of the intermolecular forces of the substance.
23) For a particular compound, which is expected to be the largest in general?
A) the heat required to raise the temperature of one mole of the gas 10.0°C
B) the heat required to raise the temperature of one mole of the liquid 10.0°C
C) the molar heat of fusion at the normal melting point
D) the molar heat of vaporization at the normal boiling point
24) Which of the following phase changes has a positive value for its entropy change?
A) boiling water
B) formation of raindrops from a cloud
C) making dry ice from gaseous CO2
D) making ice cubes from liquid water
25) For which of the following phase changes is the sign of ΔS negative?
A) boiling of water
B) formation of snow from water vapor in clouds
C) melting of ice cream
D) sublimation of I2
26) When a substance melts at its normal melting point, the sign of △H is ________ and the sign
of △S of this phase change is ________.
A) + , –
B) – , +
C) + , +
D) – , –
27) Ethyl chloride, C2H5Cl, is used as a local anesthetic. It works by cooling tissue as it
vaporizes. The heat of vaporization is 26.4 kJ/mol. How much heat could be removed by 10.0 g
of ethyl chloride?
A) 4.09 kJ
B) 170 kJ
C) 264 kJ
D) 1700 kJ
28) Bromine is one of only two elements that is a liquid at room temperature. Bromine has a heat
of vaporization of 30.91 kJ/mol and its boiling point is 59°C. What is the entropy of vaporization
for bromine?
A) –301 J/(mol ∙ K)
B) –93.1 J/(mol ∙ K)
C) 10.7 J/(mol ∙ K)
D) 93.1 J/(mol ∙ K)
29) CFC-11 (trichlorofluoromethane, CCl3F) has been used for many years as the working fluid
in refrigerators. Given its heat of vaporization is 26.88 kJ/mol and its entropy of vaporization is
90.51 J/(mol ∙ K), what is the boiling point of CFC-11?
A) -272.9°C
B) 0.297°C
C) 2.44°C
D) 23.8°C
30) How much heat is released when 75.0 g of steam at 100.0°C is cooled to ice at -15.0°C? The
enthalpy of vaporization of water is 40.67 kJ/mol, the enthalpy of fusion for water is 6.01 kJ/mol,
the molar heat capacity of liquid water is 75.4 J/(mol ∙ °C), and the molar heat capacity of ice is
36.4 J/(mol ∙ °C).
A) 54.8 kJ
B) 195 kJ
C) 228 kJ
D) 248 kJ
31) For the process: HNO3(g) ⇌ HNO3(l)
ΔH° is –39.04 kJ/mol and ΔS° is –111.74 J/(mol ∙ K). What is the normal boiling point of pure
HNO3?
A) 2.86°C
B) 76.2°C
C) 270.3°C
D) 349.4°C
32) When a liquid is heated at its boiling point, the
A) covalent bonds are broken, allowing vaporization to occur.
B) temperature of the liquid increases.
C) temperature of the liquid remains the same as long as any liquid is present.
D) temperature of the vapor phase increases.
33) As a liquid evaporates at a temperature below its boiling point, the temperature of the liquid
A) decreases.
B) decreases at low temperatures, but increases at high temperatures.
C) increases.
D) remains unchanged.
34) Molecules of a liquid can pass into the vapor phase only if the
A) liquid has little surface tension.
B) molecules have sufficient kinetic energy to overcome the intermolecular forces in the liquid.
C) temperature of the liquid is near its boiling point.
D) vapor pressure of the liquid is high.
35) The vapor pressure of a pure liquid increases as the
A) average kinetic energy of the molecules in the liquid phase decreases.
B) intermolecular attractive forces increase.
C) temperature of the liquid phase decreases.
D) temperature of the liquid phase increases.
36) The normal boiling point occurs when the
A) intermolecular forces within the liquid phase are broken.
B) temperature of the pure liquid equals the external temperature.
C) vapor pressure of a pure liquid equals an external pressure of one atmosphere.
D) vapor pressure of the liquid equals the external pressure.
37) Which of the following compounds has the highest boiling point?
A) H2O
B) HCl
C) H2S
D) NH3
38) Which of the following substances has the highest boiling point?
A) CH3–CH2–CH2–CH2–CH3
B) Xe
C) CH3–CH2–CH3
D) (CH3)4C
39) Which of the following compounds has the highest boiling point?
A) CH3CH2OH
B) HOCH2CH2OH
C) H3C-O-CH3
D) CH3CH2CH2CH3
40) Which of the following has the lowest boiling point?
A) Ar
B)
C) HF
D) HCl
41) Arrange the following in order of increasing boiling point.
CH3CH2OH CH3CH2CH3 H3C-O-CH3 CH3CH2NH2
I II III IV
A) IV < III < II < I
B) II < III < IV < I
C) I < IV < III < II
D) II < III < I < IV
42) The normal boiling point for HBr is higher than the normal boiling point for HCl. This can
be explained by
A) larger dipole-dipole forces for HBr.
B) larger dispersion forces for HBr.
C) larger hydrogen-bond forces for HBr.
D) larger dipole-dipole forces, larger dispersion forces, and larger hydrogen-bond forces for
HBr.
43) A kitchen pressure cooker operates at 1.50 atm. The ΔHvap of water is 40.7 kJ/mol. What is
the boiling point of water in the pressure cooker?
A) 362 K
B) 373 K
C) 385 K
D) 410 K
44) While mercury is very useful in barometers, mercury vapor is toxic. Given that mercury has
a ΔHvap of 59.11 kJ/mol and its normal boiling point is 356.7°C, calculate the vapor pressure in
mm Hg at room temperature, 25°C.
A) 2.68 x 10-3 mm Hg
B) 2.99 mm Hg
C) 372 mm Hg
D) 753 mm Hg
45) Hydroquinone is an antioxidant that is also used as a photographic reducer and developer.
The normal boiling point of hydroquinone is 310°C. Calculate the pressure at which
hydroquinone will boil at 200°C given that its is 73.38 kJ/mol.
A) 1.210 x 10-4 mm Hg
B) 1.35 mm Hg
C) 22.5 mm Hg
D) 757 mm Hg
46) The vapor pressure of liquid chloroform, CHCl3, is 400.0 torr at 24.1°C and 100.0 torr at
–6.3°C. What is ΔHvap of chloroform?
A) 15.3 kJ/mol
B) 30.1 kJ/mol
C) 57.6 kJ/mol
D) 86.7 kJ/mol
47) Solids having no ordered long-range structure are classified as
A) amorphous.
B) crystalline.
C) metallic.
D) molecular.
48) Which of the following forms a molecular solid?
A) CaO
B) C10H22
C) C(graphite)
D) gold
49) Which of the following statements is not consistent with the properties of a molecular solid?
A) a compound that conducts electricity when molten
B) a low melting solid
C) a solid formed by the combination of two nonmetallic elements
D) a solid that is a nonconductor of electricity
50) Which of the following forms an ionic solid?
A) Ag
B) C7H15NH2
C) RbI
D) SO3
51) Which of the following is an ionic solid?
A) Cl
B) N
C)
D) H
52) Which of the following is not an ionic solid?
A)
B) Cl
C) N C
D) Ba
53) A crystalline solid of unknown origin forms an aqueous solution that conducts an electrical
current. The solid has a high melting point and shatters when struck with a hammer. The solid is
likely to be
A) a covalent network solid.
B) an ionic solid.
C) a metallic solid.
D) a molecular solid.
54) Which of the following compounds forms a covalent network solid?
A) Li
B) C (diamond)
C) O2
D) CO2
55) Which of the following compounds forms a covalent network solid?
A) C8H18
B) NO2
C) SiO2
D) SnCl4
56) Which type of bonding does Mg form upon solidification?
A) covalent network
B) ionic
C) metallic
D) molecular
57) The wavelength of light used to observe an object must be ________ than the object itself.
A) larger
B) less than twice
C) of higher energy
D) of lower energy
58) The structure of a solid can be determined by diffraction of radiation in which region of the
electromagnetic radiation spectrum?
A) infrared
B) microwave
C) visible
D) X-ray
59) How many atoms are in one face-centered cubic unit cell of a metal?
A) 1
B) 2
C) 3
D) 4
60) How many atoms are in one body-centered cubic unit cell of a metal?
A) 1
B) 2
C) 3
D) 4
61) When cubic unit cells stack together, how many unit cells share a common corner?
A) 2
B) 4
C) 6
D) 8
62) How many unit cells share an atom that is on the face of a face-centered cubic unit cell?
A) 1
B) 2
C) 4
D) 8
63) Which type of spherical packing has the most unused space?
A) body-centered cubic
B) cubic closest-packed
C) cubic closest-packed and hexagonal closest-packed
D) simple cubic
64) Iron crystallizes in a body-centered cubic cell having an edge length of 287 pm. What is the
density of iron in g/cm3.
A) 1.99
B) 7.85
C) 11.9
D) 15.9
65) What is the edge length of a face-centered cubic unit cell made up of atoms having a radius
of 175 pm?
A) 247 pm
B) 495 pm
C) 700 pm
D) 1400 pm
66) Rhodium has a face-centered cubic structure and has a density of 12.4 g/cm3. What is its
atomic radius?
A) 134 pm
B) 268 pm
C) 380 pm
D) 1070 pm
67) Silver crystallizes in a face-centered cubic structure. What is the edge length of the unit cell
if the atomic radius of silver is 144 pm?
A) 204 pm
B) 288 pm
C) 333 pm
D) 407 pm
68) An element forms a body-centered cubic crystalline substance. The edge length of the unit
cell is 287 pm and the density of the crystal is 7.92 g/cm3. Calculate the atomic weight of the
substance.
A) 45.0 amu
B) 48.0 amu
C) 56.4 amu
D) 63.5 amu
69) Cesium has a radius of 272 pm and crystallizes in a face-centered cubic unit cell. What is the
edge length of the unit cell?
A) 314 pm
B) 385 pm
C) 544 pm
D) 769 pm
70) Manganese crystallizes in a body-centered cubic structure. What is the coordination number
of each atom?
A) 4
B) 6
C) 8
D) 12
71) Cubic closest-packing
A) has a body-centered cubic unit cell.
B) has a face-centered cubic unit cell.
C) has a simple cubic unit cell.
D) has the same unit cell as hexagonal closest-packing.
72) The highest coordination number for spherical packing is found in the
A) body-centered cubic structure.
B) simple cubic structure.
C) body-centered cubic and face-centered cubic.
D) cubic closest-packing and hexagonal closest packing.
73) KCl crystallizes in a cubic unit cell with Cl– ions on each corner and each face. How many
K+ ions and Cl– ions are in each unit cell of KCl?
A) 1 K+ ion and 1 Cl– ion
B) 2 K+ ions and 2 Cl– ions
C) 4 K+ ions and 4 Cl– ions
D) 8 K+ ions and 8 Cl– ions
74) An ionic compound crystallizes in a unit cell having a face-centered cubic array of anions,
X–, and half of the tetrahedral holes filled with metal ions, Mn+ The empirical formula of this
ionic compound is
A) MX.
B) MX2.
C) M2X.
D) M2X7.
75) An ionic compound crystallizes in a unit cell having a face-centered cubic array of metal
ions, Mn+, and all of the tetrahedral holes occupied by anions, X–. The empirical formula of this
ionic compound is
A) MX.
B) MX2.
C) M2X.
D) M7X4.
76) The edge length of a face-centered cubic lattice of NaCl is 564 pm. What is the density of
NaCl in g/cm3?
A) 0.720
B) 1.08
C) 2.16
D) 4.32
77) How many Cl– ions are around each K+ ion in KCl, which has a cubic unit cell with Cl– ions
on each corner and each face?
A) 1
B) 4
C) 6
D) 8
78) A binary ionic compound, MxAy, crystallizes in a cubic structure that contains eight anions
(A) entirely within its unit cell and a cation (M) on each corner and on each face. What is the
empirical formula of this compound?
A) MA
B) MA2
C) M2A
D) M4A8
79) O2 and O3 are ________ of oxygen.
A) allotropes
B) isomers
C) isotopes
D) stereomers
80) Which of the following is not an allotrope of carbon?
A) coal
B) diamond
C) fullerene
D) graphite
81) The layers of graphite are held together by
A) covalent bonds.
B) dipole-dipole forces.
C) London dispersion forces.
D) all of the above
82) Diamond is held together by
A) covalent bonds.
B) dipole-dipole forces.
C) London dispersion forces.
D) all of the above
83) Pencil lead is actually
A) fullerene.
B) graphite.
C) lead.
D) silica.
84) The critical temperature of a substance is the
A) highest temperature at which the liquid phase can exist in equilibrium with the gas phase.
B) temperature above which the compound decomposes.
C) temperature at which all three phases can exist in equilibrium.
D) temperature at which sublimation occurs.