Deck 12: Intermolecular Attractions and the Properties of Liquids and Solids

Question 1

The term "London forces"is a synonym for

A)ion-ion forces.
B)permanent dipole-permanent dipole interactions.
C)hydrogen bonding.
D)instantaneous dipole-instantaneous dipole interactions.
E)instantaneous dipole-induced dipole interactions.

Answer 1

instantaneous dipole-induced dipole interactions.

Question 2

Which molecule is most polarizable and subject to significant instantaneous dipole-induced dipole forces?

A)H₃C-Br
B)H₃C-Cl
C)H₃C-F
D)H₃C-H
E)H₃C-I

Answer 2

H₃C-I

Question 3

Which molecule is most polarizable and subject to the greatest instantaneous dipole-induced dipole forces?

A)CH₄
B)C₂H₆
C)C₃H₈
D)C₄H₁₀
E)C₅H₁₂

Answer 3

C₅H₁₂

Question 4

For small molecules of comparable molecular weight, which one of the following choices lists the intermolecular forces in the order of increasing strength?

A)hydrogen bonds < dipole-dipole forces < London forces
B)dipole-dipole forces < hydrogen bonds < London forces
C)London forces < hydrogen bonds < dipole-dipole forces
D)hydrogen bonds < London forces < dipole-dipole forces
E)London forces < dipole-dipole forces < hydrogen bonds

Question 5

What compound will not exhibit hydrogen bonding in the liquid state?

A)CH₃-CH₂-Br
B)CH₃-CH₂-NH₂
C)CH₃-CH₂-CH₂-OH
D)CH₃-NH-CH₃
E)NH₂-OH

Question 6

Which covalent compound will exhibit hydrogen bonding in the liquid state?

A)CH₂F₂
B)Cl₂NH
C)H₂PCl
D)HBr
E)NCl₃

Question 7

Which covalent compound will exhibit hydrogen bonding in the liquid state?

A)CCl₂F₂
B)H₂PCl
C)HCl
D)NH₂OH
E)NF₃

Question 8

Which covalent compound will exhibit hydrogen bonding in the liquid state?

A)PH₃
B)H₂
C)CH₄
D)NH₃
E)H₂S

Question 9

Which compound will have the strongest intermolecular forces?

A)CH₃-CH₂-H
B)CH₃-CH₂-O-H
C)CH₃-CH₂-PH₂
D)CH₃-CH₂-S-H
E)CH₃-CH₂-Se-H

Question 10

Which compound will have the weakest intermolecular forces?

A)CH₃-CH₂-H
B)CH₃-CH₂-O-H
C)CH₃-CH₂-PH₂
D)CH₃-CH₂-S-H
E)CH₃-CH₂-Se-H

Question 11

The strongest intermolecular forces between molecules of NO are

A)covalent bonds.
B)dipole-dipole interactions.
C)ionic bonds.
D)hydrogen bonds.
E)London forces.

Question 12

Which compound is expected to exhibit hydrogen bonding?

A)CH₃-CH₂-H
B)CH₃-CH₂-O-H
C)CH₃-CH₂-PH₂
D)CH₃-CH₂-S-H
E)CH₃-CH₂-Se-H

Question 13

At 1.0 atm pressure, ice (solid H₂O)floats in water instead of sinking. The reason for this is

A)when water freezes, it expands instead of contracting.
B)the fusion process is endothermic, therefore the solid will float.
C)the triple point has a lower temperature than the freezing point for water.
D)the critical temperature has a higher temperature than the normal boiling point.
E)the triple point corresponds to a pressure below 1 standard atmosphere.

Question 14

The property that measures or describes the magnitude of resistance to flow in a liquid is called

A)London forces.
B)malleability.
C)surface tension.
D)vapor pressure.
E)viscosity.

Question 15

Which causes surface tension?

A)more molecules present on a surface than within a liquid
B)a liquid forming as much surface area as possible
C)surface molecules having fewer molecular neighbors than interior molecules
D)a higher viscosity within a liquid than at the surface of a liquid
E)the largest average size molecules moving toward the surface of a liquid

Question 16

The presence of which intermolecular force would lead to the highest viscosity within a liquid?

A)dipole-dipole
B)London
C)dispersion
D)Hydrogen bonding
E)induced dipole

Question 17

When a liquid undergoes a change of state to a gas, the process is called

A)condensation.
B)deposition.
C)fusion.
D)sublimation.
E)evaporation.

Question 18

When a solid undergoes a change of state to a gas, the process is called

A)condensation.
B)deposition.
C)fusion.
D)sublimation.
E)evaporation.

Question 19

When a gas undergoes a change of state to a liquid, the process is called

A)condensation.
B)deposition.
C)fusion.
D)sublimation.
E)evaporation.

Question 20

Which of the following is not a factor that directly affects the viscosity of a liquid?

A)length of the molecule
B)polarizability
C)density
D)branching of molecule
E)temperature

Question 21

Which of the following organic liquids would best demonstrate wetting on a clean glass surface?

A)carbon tetrachloride (CCl₄)
B)octane (C₈H₁₈)
C)hexane (C₆H₁₄)
D)ethylene glycol (HO-CH₂-CH₂-OH)
E)heptane (C₇H₁₆)

Question 22

Which of the following organic liquids would have the strongest surface tension?

A)ethanol (CH₃-CH₂-OH)
B)octane (C₈H₁₈)
C)hexane (C₆H₁₄)
D)ethylene glycol (HO-CH₂-CH₂-OH)
E)heptanes (C₇H₁₆)

Question 23

A liquid in a covered container is in equilibrium with its vapor. If the cover is removed, what is the immediate result?

A)The average kinetic energy increases.
B)The evaporation rate decreases.
C)The evaporation rate increases.
D)The condensation rate decreases.
E)The condensation rate increases.

Question 24

Which of the following liquids, at the same temperature, has the lowest vapor pressure?

A)CH₃-CH₂-F
B)CH₃-CH₂-CH₃
C)CH₃-CH₂-CH₂-CH₃
D)CH₃-CH₂-O-H
E)CH₃-O-CH₃

Question 25

Which of the following liquids, at the same temperature, has the lowest vapor pressure?

A)CH₃-Br
B)CH₃-Cl
C)CH₃-F
D)CH₃-H
E)CH₃-I

Question 26

Which of the following liquids, at the same temperature, has the highest vapor pressure?

A)CH₃-CH₂-H
B)CH₃-O-CH₃
C)CH₃-CH₂-CH₂-CH₃
D)CH₃-CH₂-CH₃
E)CH₃-CH₂-S-H

Question 27

Which of the following liquids, at the same temperature, has the highest vapor pressure?

A)CH₃-Br
B)CH₃-Cl
C)CH₃-F
D)CH₃-H
E)CH₃-I

Question 28

Which of the following liquids, at the same temperature, has the highest vapor pressure?

A)CH₃-Hg-CH₃
B)CH₃-O-CH₃
C)CH₃-S-CH₃
D)CH₃-Se-CH₃
E)CH₃-Te-CH₃

Question 29

The vapor pressure of a liquid increases with increasing temperature. The temperature at which the vapor pressure is equal to the prevailing outside atmospheric pressure is

A)the boiling point.
B)the flash point.
C)the vaporization point.
D)100 °C.
E)the normal boiling point.

Question 30

The temperature at which the vapor pressure is equal to 1 atm, 760 torr, or 101,325 Pa is defined as

A)the melting point.
B)the flash point.
C)the vaporization point.
D)100°C.
E)the normal boiling point.

Question 31

Which compound should have the lowest boiling point?

A)CH₃-Br
B)CH₃-Cl
C)CH₃-F
D)CH₃-H
E)CH₃-I

Question 32

Which compound should have the lowest boiling point?

A)CH₃-Hg-CH₃
B)CH₃-O-CH₃
C)CH₃-S-CH₃
D)CH₃-Se-CH₃
E)CH₃-Te-CH₃

Question 33

Which compound should have the highest boiling point?

A)CH₃-Br
B)CH₃-Cl
C)CH₃-F
D)CH₃-H
E)CH₃-I

Question 34

Which compound should have the highest boiling point?

A)CH₃-Hg-CH₃
B)CH₃-O-CH₃
C)CH₃-S-CH₃
D)CH₃-Se-CH₃
E)CH₃-Te-CH₃

Question 35

Which factor affects the normal boiling point of a liquid?

A)atmospheric pressure
B)rate of condensation
C)rate of evaporation
D)strength of the intermolecular forces
E)rate of temperature increase

Question 36

Which of the following would be expected to have the lowest vapor pressure at room temperature?

A)dimethyl sulfoxide, boiling point = 189°C
B)1-pentanol, boiling point = 137°C
C)diethyl ether, boiling point = 34.6°C
D)acetone, boiling point = 56°C
E)The vapor pressure of each of the liquids at room temperature would be the same.

Question 37

Given the following substances and their normal boiling points, in °C: Which ranking correctly lists some of these substances in order of decreasing vapor pressure at 20°C?

A)C > R > D
B)D > T > R
C)R > M > D
D)C > D > M
E)D > R > M

Question 38

Given the following substances and their normal boiling points, in °C: Which ranking correctly lists some of these substances in order of increasing vapor pressure at 20°C?

A)C < R < D
B)D < R < C
C)R < T < D
D)C < D < M
E)D < M < R

Question 39

Given the following substances and their normal boiling points, in °C: Which ranking correctly lists some of these liquids in order of decreasing intermolecular forces at 20°C?

A)C > R > D
B)D > C > R
C)R > T > D
D)C > D > M
E)D > R > C

Question 40

Given the following substances and their normal boiling points, in °C: Which ranking correctly lists some of these liquids in order of increasing intermolecular forces at 20°C?

A)C < R < D
B)D < T < R
C)R < T < C
D)C < D < M
E)D < R < M

Question 41

In order to boil water, we need to supply heat. This is in order to

A)decrease the kinetic energy of the molecules.
B)disrupt ionic interactions.
C)disrupt hydrogen bonding.
D)decrease the potential energy of the molecules.
E)All of the above

Question 42

Benzene, C₆H₈, has an enthalpy of fusion of 127.4 J g^-1 and its melting point temperature is 5.53°C. How much heat is required to transform 80.0 g of solid benzene at 5.53°C into liquid benzene, also at 5.53°C?

A)705 J
B)10.2 kJ
C)14.4 kJ
D)19.3 kJ
E)22.3 kJ

Question 43

p-Xylene, C₈H₁₀, has an enthalpy of fusion of 158.3 J g^-1 and its melting point temperature is 13.2°C. How much heat is required to transform 115 g of solid p-xylene at 13.2°C into liquid p-xylene, also at 13.2°C?

A)1.52 kJ
B)2.09 kJ
C)18.2 kJ
D)32.9 kJ
E)41.8 kJ

Question 44

Benzophenone, C₁₃H₁₀O, has a heat of fusion of 98.45 J g^-1 and its melting point temperature is 47.85°C. How much heat is required to transform 126 g of solid benzophenone at 47.85°C into liquid benzophenone, also at 47.85°C?

A)4.71 kJ
B)6.03 kJ
C)12.4 kJ
D)31.6 kJ
E)40.4 kJ

Question 45

Substance A has a normal melting point of -25.0°C, a heat of fusion of 1200 J g^-1; specific heats for the solid and the liquid are 3.00 and 6.20 J g^-1 °C ^-1, respectively. How much heat will be required to change 150 grams of substance A from a solid at -40.0°C to a liquid at +70.0°C?

A)1.52 × 10⁵ J
B)1.81 × 10⁵ J
C)2.21 × 10³ J
D)2.29 × 10⁵ J
E)2.75 × 10⁵ J

Question 46

A solid with a molecular weight of 174.0 g/mol is at its melting point. If this solid requires 21.3 kJ of heat to melt 34.0 g, what is the molar heat of fusion of this solid (in kJ/mol)

A)3.60 × 10^-3 kJ/mol
B)4.16 kJ/mol
C)2.40 × 10^-1 kJ/mol
D)109 kJ/mol
E)1.26 × 10⁵ kJ/mol

Question 47

A solid with a molecular weight of 148.0 g/mol is already at its melting point. If 18.6 g of this solid requires 4.838 kJ of heat to melt it, what is the molar heat of fusion (in kJ/mol)?

A)1.33 × 10⁴ kJ/mol
B)0.608 kJ/mol
C)569 kJ/mol
D)0.0260 kJ/mol
E)38.4 kJ/mol

Question 48

22.4 g of a solid with a molecular weight of 148.0 g/mol is at its melting point. If this solid requires 5.358 kJ of heat to melt it, what is the molar heat of fusion, in kJ/mol, for this solid?

A)1.23 × 10⁴ kJ/mol
B)0.811 kJ/mol
C)35.4 kJ/mol
D)0.0282 kJ/mol
E)1.78 × 10⁴ kJ/mol

Question 49

Given the phase changes: condensation, freezing, fusion, sublimation, and vaporization. Which of these phase changes is/are endothermic?

A)condensation and freezing only
B)fusion only
C)fusion and vaporization only
D)fusion and sublimation only
E)sublimation, fusion, and vaporization only

Question 50

Supercooling is defined as

A)the extremely rapid cooling of a vapor to form a liquid.
B)the use of extremely cold refrigerants to achieve smaller crystal size when liquids are frozen.
C)the extremely rapid cooling of a liquid to form a softer crystalline solid.
D)the cooling of a liquid to a temperature below its melting point without solidification.
E)the cooling of a substance to absolute zero.

Question 51

Which of the following compounds should have the largest value for heat of vaporization ( $\Delta$ H_vap)?

A)CH₃-Br
B)CH₃-Cl
C)CH₃-F
D)CH₃-H
E)CH₃-I

Question 52

Which of the following compounds should have the largest value for heat of fusion ( $\Delta$ H_fus)?

A)NH₃
B)CH₃-Cl
C)N₂
D)HCl

Question 53

Dioxane, C₄H₈O₂, has an enthalpy of fusion of 145.8 J g^-1 and its melting point temperature is 11.0°C. How much heat is required to transform 142 g of solid dioxane, into liquid dioxane, at 11.0°C?

A)1.60 kJ
B)2.59 kJ
C)20.7 kJ
D)22.8 kJ
E)40.3 kJ

Question 54

A substance, B, has a normal boiling point of +89.3°C, and a heat of vaporization of 260 J/g. How much heat is required to change 150 grams of B from a liquid at 89.3°C to a gas at 89.3°C?

A)5.2 × 10² J
B)3.9 × 10⁴ J
C)4.4 × 10⁵ J
D)1.1 × 10⁵ J
E)1.6 × 10⁵ J

Question 55

Evaporation

A)is an endothermic process.
B)is an exothermic process.
C)involves breaking intermolecular forces.
D)decreases the temperature on the surface where it occurs.
E)A, C, and D

Question 56

An isobar is a line of constant pressure which runs parallel to the temperature axis on the phase diagram for a substance. As we vary temperature along an isobar that lies below the triple point, which process would never be observed?

A)decrease in volume
B)deposition
C)expansion
D)fusion
E)sublimation

Question 57

The triple point of a substance is the temperature and pressure at which

A)all three physical states cease to exist.
B)sublimation, fusion, and condensation are taking place simultaneously.
C)the solid will always float on the liquid for all substances.
D)the vapor pressure of the liquid is higher than the vapor pressure of the solid.
E)the vapor pressure of the solid is higher than the vapor pressure of the liquid.

Question 58

The following questions refer to the phase diagram below. Gas, liquid, and solid phases are all present, but not labeled.

-At the temperature and pressure of point d, which statement below is true?

A)The substance will sublime.
B)There will be an equilibrium between the solid phase and the gaseous phase.
C)Vaporization and deposition will take place simultaneously.
D)Condensation and evaporation will take place simultaneously.
E)The substance will be a supercritical fluid.

Question 59

The following questions refer to the phase diagram below. Gas, liquid, and solid phases are all present, but not labeled.

-At the temperature and pressure of point e, which statement below is true?

A)The substance will sublime.
B)There will be an equilibrium between the solid phase and the gaseous phase.
C)Vaporization and deposition will take place simultaneously.
D)Melting and freezing will take place simultaneously.
E)Melting and vaporization will take place simultaneously.

Question 60

The following questions refer to the phase diagram below. Gas, liquid, and solid phases are all present, but not labeled.

-Starting at the temperature and pressure of b, if the temperature is increased at constant pressure, ultimately

A)the substance will sublime.
B)the substance will undergo fusion.
C)the substance will undergo deposition.
D)the substance will freeze.
E)the substance will be a supercritical fluid.

Question 61

The following questions refer to the phase diagram below. Gas, liquid, and solid phases are all present, but not labeled.

-Starting at the temperature and pressure of c, if the pressure is increased at constant temperature, ultimately

A)the substance will sublime.
B)the substance will undergo fusion.
C)the substance will undergo deposition.
D)the substance will freeze.
E)the substance will undergo condensation.

Question 62

The following questions refer to the phase diagram below.

-What phase should this substance exist as, at a pressure of 1500 torr and a temperature of -20°C?

A)solid
B)liquid
C)gas
D)supercritical fluid
E)unable to tell

Question 63

The following questions refer to the phase diagram below.

-What phase should this substance exist as, at a pressure of 2000 torr and a temperature of 20°C?

A)solid
B)liquid
C)gas
D)supercritical fluid
E)unable to tell

Question 64

The following questions refer to the phase diagram below.

-What phase should this substance exist as, at a pressure of 2000 torr and a temperature of -70°C?

A)solid
B)liquid
C)gas
D)supercritical fluid
E)unable to tell

Question 65

The following questions refer to the phase diagram below.

-Which of the following values of temperature and pressure most closely correspond to the triple point of this substance?

A)-21°C and 1000 torr
B)0°C and 1000 torr.
C)-57°C and 740 torr
D)-50°C and 4500 torr
E)0°C and 1760 torr

Question 66

Which compound cannot be liquefied by compression, at a temperature of 25.0°C?

A)C₂H₄, critical point: 9.9°C, 50.5 atm
B)CH₃Cl, critical point: 144.0°C, 66.0 atm
C)C₂H₂, critical point: 35.5°C, 61.6 atm
D)C₂H₆, critical point: 32.2°C, 48.2 atm
E)SO₂, critical point: 158.0°C, 78.0 atm

Question 67

The critical temperature of a substance is

A)always higher than the triple point temperature.
B)the temperature below which it cannot exist in the liquid state.
C)the temperature which is always higher than the Kelvin point.
D)the temperature below which it cannot be liquefied by increasing the pressure.
E)the temperature below which it cannot be supercooled.

Question 68

Which compound cannot be liquefied by compression, at a temperature of 25.0°C?

A)CH₃Cl, critical point: 144.0°C, 66.0 atm
B)C₂H₂, critical point: 35.5°C, 61.6 atm
C)C₂H₆, critical point: 32.2°C, 48.2 atm
D)SiF₄, critical point: -14.1°C, 36.7 atm
E)SO₂, critical point: 158.0°C, 78.0 atm

Question 69

The normal boiling point of acetic acid, HC₂H₃O₂, is 117.9°C, and its heat of vaporization is 39,690 J/mol. What is its vapor pressure at 100.0°C?

A)423.2 torr
B)479.7 torr
C)586.6 torr
D)616.2 torr
E)694.4 torr

Question 70

Find the boiling temperature at 760 torr of an isomer of octane, C₈H₁₈, if its heat of vaporization is 38,210 J mol^-1 and its vapor pressure at 110.0°C is 638.43 torr.

A)111.52°C
B)113.22°C
C)115.00°C
D)115.65°C
E)118.30°C

Question 71

Hexane (C₆H₁₄)boils at 68.73°C at 760 torr. The heat of vaporization for hexane is28.9 kJ/mol. What is the vapor pressure of hexane at 30°C?

A)207 torr
B)546 torr
C)2786 torr
D)759 torr
E)2396 torr

Question 72

The normal boiling point of 2,3,4-trimethypentane, C₈H₁₈, is 113.47°C, and its heat of vaporization is 37,600 J mol^-1. What is its vapor pressure at 105.5°C?

A)479.7 torr
B)586.6 torr
C)594.1 torr
D)616.2 torr
E)694.4 torr

Question 73

Portions of how many different atoms are in one simple cubic unit cell?

A)2
B)3
C)4
D)6
E)8

Question 74

Which type of lattice structures have lattice points on all of the faces?

A)simple cubic structures
B)base-centered structures
C)face-centered structures
D)body-centered structures
E)both body-centered and base-centered structures

Question 75

Which type of unit cell has lattice points at each corner, and one in the center of the cell?

A)face-centered cubic
B)simple cubic
C)body-centered cubic
D)edge-centered cubic
E)hexagonal-centered cubic

Question 76

In a one-element solid with a face-centered cubic structure, how many atoms are in one unit cell?

A)1
B)2
C)3
D)4
E)5

Question 77

In a one-element solid with a simple cubic crystal structure, how many atoms are in one unit cell?

A)1
B)2
C)3
D)4
E)5

Question 78

A new compound, boganium sulfide, has been discovered. X-ray crystallographic studies reveal that it has a cubic unit cell with a sulfide ion at each of the corner lattice points, a sulfide ion at the geometric center of the unit cell, and a boganium ion in the center of each of the cube faces in the unit cell. Based on this structure, the formula for the compound should be

A)Bo₃S
B)Bo₃S₂
C)BoS
D)Bo₂S₃
E)BoS₃

Question 79

What type of crystal lattice is found in a sample of table salt, NaCl?

A)simple cubic
B)base-centered cubic
C)body-centered cubic
D)face-centered cubic
E)orthorhombic-centered cubic

Question 80

How many atoms are contained in one unit cell of metallic tungsten, if it forms a face-centered cubic unit cell?

A)2
B)4
C)8
D)9
E)14