Chapter 13
Intermolecular Forces,
Liquids, and Solids
Which of the following molecules can hydrogen
bond with itself?
1.
2.
3.
4.
5.
1, 2
2, 3
3, 4
1, 2, 3
1, 2, 3, 4
O
CH2F2
NH3
CH3-O-H
H3C C CH3
1
2
3
4
Which of the following molecules can hydrogen
bond with itself?
1.
2.
3.
4.
5.
1, 2
2, 3
3, 4
1, 2, 3
1, 2, 3, 4
O
CH2F2
NH3
CH3-O-H
H3C C CH3
1
2
3
4
Arrange the following according to increasing
melting point.
Kr I
O
He
2
1.
2.
3.
4.
5.
O2 < He < I2 < Kr
He < O2 < I2 < Kr
He < O2 < Kr < I2
I2 < Kr < O2 < He
I2 < Kr < He < O2
2
Arrange the following according to increasing
melting point.
Kr I
O
He
2
1.
2.
3.
4.
5.
O2 < He < I2 < Kr
He < O2 < I2 < Kr
He < O2 < Kr < I2
I2 < Kr < O2 < He
I2 < Kr < He < O2
2
Arrange the following according to increasing
melting point.
MgO CO2 O2 H2O
1.
2.
3.
4.
5.
MgO < H2O < CO2 < O2
O2 < CO2 < H2O < MgO
O2 < H2O < CO2 < MgO
H2O < O2 < MgO < CO2
O2 < CO2 < H2O < MgO
Arrange the following according to increasing
melting point.
MgO CO2 O2 H2O
1.
2.
3.
4.
5.
MgO < H2O < CO2 < O2
O2 < CO2 < H2O < MgO
O2 < H2O < CO2 < MgO
H2O < O2 < MgO < CO2
O2 < CO2 < H2O < MgO
Arrange the following according to increasing
vapor pressure.
NH3 I2 Br2 CH4
1.
2.
3.
4.
5.
NH3 < I2 < Br2 < CH4
I2 < Br2 < NH3 < CH4
NH3 < CH4 < I2 < Br2
NH3 < I2 < CH4 < Br2
CH4 < NH3 < Br2 < I2
Arrange the following according to increasing
vapor pressure.
NH3 I2 Br2 CH4
1.
2.
3.
4.
5.
NH3 < I2 < Br2 < CH4
I2 < Br2 < NH3 < CH4
NH3 < CH4 < I2 < Br2
NH3 < I2 < CH4 < Br2
CH4 < NH3 < Br2 < I2
Which does not represent close packing?
1.
2.
3.
4.
5.
ABABAB
ABCABC
ABACBAC
AABCABB
CACBABC
Which does not represent close packing?
1.
2.
3.
4.
5.
ABABAB
ABCABC
ABACBAC
AABCABB
CACBABC
1.
2.
3.
4.
5.
Boiling point ~120°C
Boiling point ~95°C
Boiling point ~75°C
Melting point ~95°C
Melting point ~75°C
Vapor Pressure (mm Hg)
Which statement
is true?
800
600
400
200
0
0
25
50
75
100
Temperature (°C)
1.
2.
3.
4.
5.
Boiling point ~120°C
Boiling point ~95°C
Boiling point ~75°C
Melting point ~95°C
Melting point ~75°C
Vapor Pressure (mm Hg)
Which statement
is true?
800
600
400
200
0
0
25
50
75
100
Temperature (°C)
Lead crystallizes in a face-centered cubic unit
cell. How many lead atoms are in one unit cell?
1.
2.
3.
4.
5.
1
2
4
10
14
Lead crystallizes in a face-centered cubic unit
cell. How many lead atoms are in one unit cell?
1.
2.
3.
4.
5.
1
2
4
10
14
How many tetrahedral holes are in a facecentered cubic unit cell?
1.
2.
3.
4.
5.
2
4
6
8
14
How many tetrahedral holes are in a facecentered cubic unit cell?
1.
2.
3.
4.
5.
2
4
6
8
14
Of the following substances, predict
which has the highest boiling point
based on intermolecular forces.
1. Propane, C3H8
2. Dimethyl ether,
CH3OCH3
3. Methyl chloride, CH3Cl
4. Acetaldehyde, CH3CHO
5. Acetonitrile, CH3CN
Of the following substances, predict
which has the highest boiling point
based on intermolecular forces.
1. Propane, C3H8
2. Dimethyl ether,
CH3OCH3
3. Methyl chloride, CH3Cl
4. Acetaldehyde, CH3CHO
5. Acetonitrile, CH3CN
Correct Answer:
1. Propane, C3H8
2. Dimethyl ether,
CH3OCH3
3. Methyl chloride, CH3Cl
4. Acetaldehyde, CH3CHO
5. Acetonitrile, CH3CN
Each of these molecules has almost the same
molecular weight; however, acetonitrile has the
largest dipole moment (3.9 D) and hence the largest
dipole-dipole forces. Thus it has the highest boiling
point.
Of the following substances, predict
which has the lowest boiling point
based on London dispersion forces.
1.
2.
3.
4.
5.
He
Ne
Ar
Kr
Xe
Correct Answer:
1.
2.
3.
4.
5.
He
Ne
Ar
Kr
Xe
More massive species have more polarizability
and stronger London dispersion forces;
consequently, amongst the noble gases He has
the lowest boiling point.
Of the following substances, predict
which has the highest boiling point
based upon intermolecular forces?
1.
2.
3.
4.
5.
CH4
H2O
H2S
SiH4
H2Se
NH ……. O=C
Correct Answer:
1.
2.
3.
4.
5.
CH4
H2O
H2S
SiH4
H2Se
Of these, only H2O has any
hydrogen bonding.
Hydrogen bonding
substantially increases the
intermolecular forces, and
hence the boiling point.
Which one of the following phase
changes is an exothermic process?
1.
2.
3.
4.
Sublimation
Vaporization
Condensation
Melting
Correct Answer:
1.
2.
3.
4.
Sublimation
Vaporization
Condensation
Melting
All the other
phase-change
processes
listed are
endothermic.
How much energy is required to raise the
temperature of 1800. g ice at 0°C to 10°C?
DHfus = 6.01 kJ/mol, heat capacity of water
is 75.2 J/mol-K.
1.
2.
3.
4.
5.
60.1 kJ
75.2 kJ
135 kJ
601 kJ
676 kJ
Correct Answer:
1.
2.
3.
4.
5.
60.1 kJ
75.2 kJ
135 kJ
601 kJ
676 kJ
There are 100 moles of ice, so
the enthalpy of fusion is:
DH =(6.01 kJ/mol)(100 mol) = 601
kJ.
To raise the water temperature
10°C requires
q = (75.2 J/mol-K)(100 mol)(10°C )
= 75.2 kJ.
Total energy = 601 kJ +75 kJ =
676 kJ
In the unlabeled phase diagram below,
the line segment from A to B separates
which two phases?
D
B
1. Gas-liquid
2. Liquid-solid
3. Solid-gas
A
C
Temperature
Correct Answer:
D
B
1. Gas-liquid
2. Liquid-solid
3. Solid-gas
A
C
Temperature
Quartz is an example of which type of
solid: crystalline or amorphous?
1. Crystalline
2. Amorphous
Correct Answer:
1. Crystalline
2. Amorphous
In quartz, the SiO bonds
are arranged in regular,
defined arrays.
What are the net number of Na+ and Cl
ions in the NaCl unit cell represented
below?
1.
2.
3.
4.
5.
4 Na+, 4 Cl
2 Na+, 1 Cl
2 Na+, 2 Cl
1 Na+, 2 Cl
1 Na+, 1 Cl
Correct Answer:
There are 4 Na+ resulting from:
(1/4 Na+/edge)(12 edges) = 3 Na+
(1 Na+/center)(1 center) = 1 Na+
There are 4 Cl− resulting from:
(1/8 Cl/corner)(8 corners) = 1 Cl
(1/2 Cl/face)(6 faces) = 3 Cl
1.
2.
3.
4.
5.
4 Na+, 4 Cl
2 Na+, 1 Cl
2 Na+, 2 Cl
1 Na+, 2 Cl
1 Na+, 1 Cl
The NaCl crystal shown below is an
example of which type of cubic lattice?
1. Primitive cubic
2. Body-centered
cubic
3. Face-centered
cubic
Correct Answer:
1. Primitive cubic
2. Body-centered
cubic
3. Face-centered
cubic
NaCl is an example
of a face-centered
crystalline lattice.
Diamond and graphite are examples of
which type of crystalline solids?
1.
2.
3.
4.
Molecular
Covalent network
Ionic
Metallic
Correct Answer:
1.
2.
3.
4.
Molecular
Covalent network
Ionic
Metallic
Diamond and graphite
are both forms of
carbon, and consist of a
network of covalent
bonds (hence covalent
network).
Correct Answer:
1. Propane, C3H8
2. Dimethyl ether,
CH3OCH3
3. Methyl chloride, CH3Cl
4. Acetaldehyde, CH3CHO
5. Acetonitrile, CH3CN
Each of these molecules has almost the same
molecular weight; however, acetonitrile has the
largest dipole moment (3.9 D) and hence the largest
dipole-dipole forces. Thus it has the highest boiling
point.
Of the following substances, predict
which has the lowest boiling point
based on London dispersion forces.
1.
2.
3.
4.
5.
He
Ne
Ar
Kr
Xe
Correct Answer:
1.
2.
3.
4.
5.
He
Ne
Ar
Kr
Xe
More massive species have more polarizability
and stronger London dispersion forces;
consequently, amongst the noble gases He has
the lowest boiling point.
Of the following substances, predict
which has the highest boiling point
based upon intermolecular forces?
1.
2.
3.
4.
5.
CH4
H2O
H2S
SiH4
H2Se
NH ……. O=C
Correct Answer:
1.
2.
3.
4.
5.
CH4
H2O
H2S
SiH4
H2Se
Of these, only H2O has any
hydrogen bonding.
Hydrogen bonding
substantially increases the
intermolecular forces, and
hence the boiling point.
Which one of the following phase
changes is an exothermic process?
1.
2.
3.
4.
Sublimation
Vaporization
Condensation
Melting
Correct Answer:
1.
2.
3.
4.
Sublimation
Vaporization
Condensation
Melting
All the other
phase-change
processes
listed are
endothermic.
How much energy is required to raise the
temperature of 1800. g ice at 0°C to 10°C?
DHfus = 6.01 kJ/mol, heat capacity of water
is 75.2 J/mol-K.
1.
2.
3.
4.
5.
60.1 kJ
75.2 kJ
135 kJ
601 kJ
676 kJ
Correct Answer:
1.
2.
3.
4.
5.
60.1 kJ
75.2 kJ
135 kJ
601 kJ
676 kJ
There are 100 moles of ice, so
the enthalpy of fusion is:
DH =(6.01 kJ/mol)(100 mol) = 601
kJ.
To raise the water temperature
10°C requires
q = (75.2 J/mol-K)(100 mol)(10°C )
= 75.2 kJ.
Total energy = 601 kJ +75 kJ =
676 kJ
In the unlabeled phase diagram below,
the line segment from A to B separates
which two phases?
D
B
1. Gas-liquid
2. Liquid-solid
3. Solid-gas
A
C
Temperature
Correct Answer:
D
B
1. Gas-liquid
2. Liquid-solid
3. Solid-gas
A
C
Temperature
Quartz is an example of which type of
solid: crystalline or amorphous?
1. Crystalline
2. Amorphous
Correct Answer:
1. Crystalline
2. Amorphous
In quartz, the SiO bonds
are arranged in regular,
defined arrays.
What are the net number of Na+ and Cl
ions in the NaCl unit cell represented
below?
1.
2.
3.
4.
5.
4 Na+, 4 Cl
2 Na+, 1 Cl
2 Na+, 2 Cl
1 Na+, 2 Cl
1 Na+, 1 Cl
Correct Answer:
There are 4 Na+ resulting from:
(1/4 Na+/edge)(12 edges) = 3 Na+
(1 Na+/center)(1 center) = 1 Na+
There are 4 Cl− resulting from:
(1/8 Cl/corner)(8 corners) = 1 Cl
(1/2 Cl/face)(6 faces) = 3 Cl
1.
2.
3.
4.
5.
4 Na+, 4 Cl
2 Na+, 1 Cl
2 Na+, 2 Cl
1 Na+, 2 Cl
1 Na+, 1 Cl
The NaCl crystal shown below is an
example of which type of cubic lattice?
1. Primitive cubic
2. Body-centered
cubic
3. Face-centered
cubic
Correct Answer:
1. Primitive cubic
2. Body-centered
cubic
3. Face-centered
cubic
NaCl is an example
of a face-centered
crystalline lattice.
Diamond and graphite are examples of
which type of crystalline solids?
1.
2.
3.
4.
Molecular
Covalent network
Ionic
Metallic
Correct Answer:
1.
2.
3.
4.
Molecular
Covalent network
Ionic
Metallic
Diamond and graphite
are both forms of
carbon, and consist of a
network of covalent
bonds (hence covalent
network).