Chapter 13Intermolecular Forces,

Liquids, and Solids

Which of the following molecules can hydrogen bond with itself?

1. 1, 22. 2, 33. 3, 44. 1, 2, 35. 1, 2, 3, 4

CH2F2 NH3 CH3-O-H CH3C CH3

O

1 2 3 4

Which of the following molecules can hydrogen bond with itself?

1. 1, 22. 2, 33. 3, 44. 1, 2, 35. 1, 2, 3, 4

CH2F2 NH3 CH3-O-H CH3C CH3

O

1 2 3 4

Arrange the following according to increasing melting point.

1. O2 < He < I2 < Kr

2. He < O2 < I2 < Kr

3. He < O2 < Kr < I2

4. I2 < Kr < O2 < He

5. I2 < Kr < He < O2

Kr I2 O2 He

Arrange the following according to increasing melting point.

1. O2 < He < I2 < Kr

2. He < O2 < I2 < Kr

3. He < O2 < Kr < I2

4. I2 < Kr < O2 < He

5. I2 < Kr < He < O2

Kr I2 O2 He

Arrange the following according to increasing melting point.

1. MgO < H2O < CO2 < O2

2. O2 < CO2 < H2O < MgO

3. O2 < H2O < CO2 < MgO

4. H2O < O2 < MgO < CO2

5. O2 < CO2 < H2O < MgO

MgO CO2 O2 H2O

Arrange the following according to increasing melting point.

1. MgO < H2O < CO2 < O2

2. O2 < CO2 < H2O < MgO

3. O2 < H2O < CO2 < MgO

4. H2O < O2 < MgO < CO2

5. O2 < CO2 < H2O < MgO

MgO CO2 O2 H2O

Arrange the following according to increasing vapor pressure.

1. NH3 < I2 < Br2 < CH4

2. I2 < Br2 < NH3 < CH4

3. NH3 < CH4 < I2 < Br2

4. NH3 < I2 < CH4 < Br2

5. CH4 < NH3 < Br2 < I2

NH3 I2 Br2 CH4

Arrange the following according to increasing vapor pressure.

1. NH3 < I2 < Br2 < CH4

2. I2 < Br2 < NH3 < CH4

3. NH3 < CH4 < I2 < Br2

4. NH3 < I2 < CH4 < Br2

5. CH4 < NH3 < Br2 < I2

NH3 I2 Br2 CH4

Which does not represent close packing?

1. ABABAB2. ABCABC3. ABACBAC 4. AABCABB5. CACBABC

Which does not represent close packing?

1. ABABAB2. ABCABC3. ABACBAC 4. AABCABB5. CACBABC

Which statement is true?

1. Boiling point ~120°C2. Boiling point ~95°C 3. Boiling point ~75°C4. Melting point ~95°C5. Melting point ~75°C

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Which statement is true?

1. Boiling point ~120°C2. Boiling point ~95°C 3. Boiling point ~75°C4. Melting point ~95°C5. Melting point ~75°C

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Lead crystallizes in a face-centered cubic unit cell. How many lead atoms are in one unit cell?

1. 12. 23. 44. 105. 14

Lead crystallizes in a face-centered cubic unit cell. How many lead atoms are in one unit cell?

1. 12. 23. 44. 105. 14

1. 22. 43. 64. 85. 14

How many tetrahedral holes are in a face- centered cubic unit cell?

1. 22. 43. 64. 85. 14

How many tetrahedral holes are in a face- centered cubic unit cell?

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, CH3Cl4. Acetaldehyde, CH3CHO5. 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, CH3Cl4. Acetaldehyde, CH3CHO5. Acetonitrile, CH3CN

Correct Answer:

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.

1. Propane, C3H8

2. Dimethyl ether, CH3OCH3

3. Methyl chloride, CH3Cl4. Acetaldehyde, CH3CHO5. Acetonitrile, CH3CN

Of the following substances, predict which has the lowest boiling point based on London dispersion forces.

1. He2. Ne3. Ar4. Kr5. Xe

Correct Answer:

More massive species have more polarizability and stronger London dispersion forces; consequently, amongst the noble gases He has the lowest boiling point.

1. He2. Ne3. Ar4. Kr5. Xe

Of the following substances, predict which has the highest boiling point based upon intermolecular forces?

1. CH4

2. H2O3. H2S4. SiH4

5. H2Se

NH ……. O=C

Correct Answer:

Of these, only H2O has any hydrogen bonding. Hydrogen bonding substantially increases the intermolecular forces, and hence the boiling point.

1. CH4

2. H2O3. H2S4. SiH4

5. H2Se

Which one of the following phase changes is an exothermic process?

1. Sublimation2. Vaporization3. Condensation4. Melting

Correct Answer:

All the other phase-change processes listed are endothermic.

1. Sublimation2. Vaporization3. Condensation4. Melting

How much energy is required to raise the temperature of 1800. g ice at 0°C to 10°C? Hfus = 6.01 kJ/mol, heat capacity of water is 75.2 J/mol-K.

1. 60.1 kJ2. 75.2 kJ3. 135 kJ4. 601 kJ5. 676 kJ

Correct Answer:

There are 100 moles of ice, so the enthalpy of fusion is:H =(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

1. 60.1 kJ2. 75.2 kJ3. 135 kJ4. 601 kJ5. 676 kJ

Temperature

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In the unlabeled phase diagram below, the line segment from A to B separates which two phases?

1. Gas-liquid2. Liquid-solid3. Solid-gas

Correct Answer:

1. Gas-liquid2. Liquid-solid3. Solid-gas

Temperature

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Quartz is an example of which type of solid: crystalline or amorphous?

1. Crystalline2. Amorphous

Correct Answer:

In quartz, the SiO bonds are arranged in regular, defined arrays.

1. Crystalline2. Amorphous

What are the net number of Na+ and Cl ions in the NaCl unit cell represented below?

1. 4 Na+, 4 Cl

2. 2 Na+, 1 Cl

3. 2 Na+, 2 Cl

4. 1 Na+, 2 Cl

5. 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. 4 Na+, 4 Cl

2. 2 Na+, 1 Cl

3. 2 Na+, 2 Cl

4. 1 Na+, 2 Cl

5. 1 Na+, 1 Cl

The NaCl crystal shown below is an example of which type of cubic lattice?

1. Primitive cubic2. Body-centered

cubic3. Face-centered

cubic

Correct Answer:

NaCl is an example

of a face-centered

crystalline lattice.

1. Primitive cubic2. Body-centered

cubic3. Face-centered

cubic

Diamond and graphite are examples of which type of crystalline solids?

1. Molecular2. Covalent network3. Ionic4. Metallic

Correct Answer:

Diamond and graphite are both forms of carbon, and consist of a network of covalent bonds (hence covalent network).

1. Molecular2. Covalent network3. Ionic4. Metallic

Correct Answer:

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.

1. Propane, C3H8

2. Dimethyl ether, CH3OCH3

3. Methyl chloride, CH3Cl4. Acetaldehyde, CH3CHO5. Acetonitrile, CH3CN

Of the following substances, predict which has the lowest boiling point based on London dispersion forces.

1. He2. Ne3. Ar4. Kr5. Xe

Correct Answer:

More massive species have more polarizability and stronger London dispersion forces; consequently, amongst the noble gases He has the lowest boiling point.

1. He2. Ne3. Ar4. Kr5. Xe

Of the following substances, predict which has the highest boiling point based upon intermolecular forces?

1. CH4

2. H2O3. H2S4. SiH4

5. H2Se

NH ……. O=C

Correct Answer:

Of these, only H2O has any hydrogen bonding. Hydrogen bonding substantially increases the intermolecular forces, and hence the boiling point.

1. CH4

2. H2O3. H2S4. SiH4

5. H2Se

Which one of the following phase changes is an exothermic process?

1. Sublimation2. Vaporization3. Condensation4. Melting

Correct Answer:

All the other phase-change processes listed are endothermic.

1. Sublimation2. Vaporization3. Condensation4. Melting

How much energy is required to raise the temperature of 1800. g ice at 0°C to 10°C? Hfus = 6.01 kJ/mol, heat capacity of water is 75.2 J/mol-K.

1. 60.1 kJ2. 75.2 kJ3. 135 kJ4. 601 kJ5. 676 kJ

Correct Answer:

There are 100 moles of ice, so the enthalpy of fusion is:H =(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

1. 60.1 kJ2. 75.2 kJ3. 135 kJ4. 601 kJ5. 676 kJ

Temperature

Pre

ssu

reAA

DD

CC

BB

In the unlabeled phase diagram below, the line segment from A to B separates which two phases?

1. Gas-liquid2. Liquid-solid3. Solid-gas

Correct Answer:

1. Gas-liquid2. Liquid-solid3. Solid-gas

Temperature

Pre

ssu

reAA

DD

CC

BB

Quartz is an example of which type of solid: crystalline or amorphous?

1. Crystalline2. Amorphous

Correct Answer:

In quartz, the SiO bonds are arranged in regular, defined arrays.

1. Crystalline2. Amorphous

What are the net number of Na+ and Cl ions in the NaCl unit cell represented below?

1. 4 Na+, 4 Cl

2. 2 Na+, 1 Cl

3. 2 Na+, 2 Cl

4. 1 Na+, 2 Cl

5. 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. 4 Na+, 4 Cl

2. 2 Na+, 1 Cl

3. 2 Na+, 2 Cl

4. 1 Na+, 2 Cl

5. 1 Na+, 1 Cl

The NaCl crystal shown below is an example of which type of cubic lattice?

1. Primitive cubic2. Body-centered

cubic3. Face-centered

cubic

Correct Answer:

NaCl is an example

of a face-centered

crystalline lattice.

1. Primitive cubic2. Body-centered

cubic3. Face-centered

cubic

Diamond and graphite are examples of which type of crystalline solids?

1. Molecular2. Covalent network3. Ionic4. Metallic

Correct Answer:

Diamond and graphite are both forms of carbon, and consist of a network of covalent bonds (hence covalent network).

1. Molecular2. Covalent network3. Ionic4. Metallic