Deck 11: Liquids, Solids, and Intermolecular Forces

Question 1

Which pairs of substances would form homogeneous solutions when combined?

A) Methanol and water
B) Diethyl ether and water
C) CH₂Cl₂ and water
D) CCl₄ and water

Answer 1

Methanol and water

Question 2

Which one of the following has a definite shape and volume?

A) gas
B) liquid
C) solid
D) none of the above

Answer 2

solid

Question 3

Choose the compound that exhibits hydrogen bonding as its strongest intermolecular force.

A) SCl₂
B) C₂H₆
C) CH₃OH
D) CH₂F₂
E) None of the above compounds exhibit hydrogen bonding.

Answer 3

CH₃OH

Question 4

Give the change in condition to go from a liquid to a gas.

A) increase heat or reduce pressure
B) increase heat or increase pressure
C) cool or reduce pressure
D) cool or increase pressure
E) none of the above

Question 5

Which pairs of substances would form homogeneous solutions when combined?

A) Hexane and water
B) Oil and water
C) KCl and water
D) CCl₄ and water

Question 6

Place the following compounds in order of decreasing strength of intermolecular forces. HF O₂ CO₂

A) HF > CO₂ > O₂
B) HF > O₂ > CO₂
C) O₂ > CO₂ > HF
D) CO₂ > HF > O₂
E) CO₂ > O₂ > HF

Question 7

Which pairs of substances would form homogeneous solutions when combined?

A) CH₂Cl₂ and water
B) Diethyl ether and water
C) Glucose and water
D) CCl₄ and water

Question 8

Identify the characteristics of a liquid.

A) indefinite shape and volume
B) indefinite shape, but definite volume
C) definite shape and volume
D) definite shape and indefinite volume

Question 9

Place the following compounds in order of increasing strength of intermolecular forces. CO₂ F₂ NH₂CH₃

A) NH₂CH₃ < CO₂ < F₂
B) F₂ < NH₂CH₃ < CO₂
C) NH₂CH₃ < F₂ < CO₂
D) F₂ < CO₂ < NH₂CH₃
E) CO₂ < NH₂CH₃ < F₂

Question 10

What is the strongest type of intermolecular force present in H₂?

A) ion-dipole
B) dipole-dipole
C) dispersion
D) hydrogen bonding
E) none of the above

Question 11

Choose the molecule or compound that exhibits dispersion forces as its strongest intermolecular force.

A) Cl₂
B) NH₃
C) HF
D) NaCl

Question 12

The forces between polar molecules is known as ________.

A) hydrogen bonding
B) ion-dipole forces
C) dipole-dipole forces
D) dispersion forces
E) ionic forces

Question 13

Which of the following statements is TRUE?

A) Intermolecular forces are generally stronger than bonding forces.
B) The potential energy of molecules decrease as they get closer to one another.
C) Energy is given off when the attraction between two molecules is broken.
D) Increasing the pressure on a solid usually causes it to become a liquid.
E) None of the above is true.

Question 14

What type of intermolecular force causes the dissolution of NaCl in water?

A) hydrogen bonding
B) dipole-dipole forces
C) ion-dipole force
D) dispersion forces
E) none of the above

Question 15

Choose the molecule or compound that exhibits dipole-dipole forces as its strongest intermolecular force.

A) H₂
B) SO₂
C) NH₃
D) CF₄
E) BCl₃

Question 16

What is the strongest type of intermolecular force present in CHF₃?

A) ion-dipole
B) dispersion
C) hydrogen bonding
D) dipole-dipole
E) none of the above

Question 17

What is the strongest type of intermolecular force present in NH₂CH₃?

A) dispersion
B) dipole-dipole
C) hydrogen bonding
D) ion-dipole
E) none of the above

Question 18

Which one of the following has a low density?

A) gas
B) liquid
C) solid
D) none of the above

Question 19

Place the following compounds in order of increasing strength of intermolecular forces. CH₄ CH₃CH₂CH₃ CH₃CH₃

A) CH₃CH₂CH₃ < CH₄ < CH₃CH₃
B) CH₃CH₂CH₃ < CH₃CH₃ < CH₄
C) CH₃CH₃ < CH₄ < CH₃CH₂CH₃
D) CH₄ < CH₃CH₂CH₃ < CH₃CH₃
E) CH₄ < CH₃CH₃ < CH₃CH₂CH₃

Question 20

What type of intermolecular force causes the dissolution of CH₃CH₂OH in water?

A) hydrogen bonding
B) dipole-dipole forces
C) ion-dipole forces
D) dispersion forces
E) none of the above

Question 21

Choose the substance with the lowest surface tension in the liquid phase.

A) CH₃SH
B) CH₃CH₂CH₂CH₃
C) C₆H₆
D) H₂O
E) (CH₃)₂CO

Question 22

Choose the pair of substances that are most likely to form a homogeneous solution.

A) CCl₄ and SCl₂
B) NF₃ and SO₂
C) CO and C₆H₆
D) NH₂CH₃ and CH₄
E) None of the pairs above will form a homogeneous solution.

Question 23

Define boiling.

A) A liquid becomes a gas.
B) A gas becomes a liquid.
C) A gas becomes a solid.
D) A solid becomes a gas.
E) A solid becomes a liquid.

Question 24

Identify the compound that does not have dipole-dipole forces as its strongest force.

A) CH₂Cl₂
B) CH₃OCH₃
C) CH₃Br
D) HCCl₃
E) CO₂

Question 25

Choose the substance with the highest surface tension in the liquid phase.

A) HOCH₂CH₂OH
B) CH₂F₂
C) CH₃CH₂F
D) CH₃CH₂OH
E) CH₃CH₂CH₃

Question 26

Choose the pair of substances that are most likely to form a homogeneous solution.

A) NaCl and Hg
B) LiF and C₆H₁₄
C) C₃H₈ and C₂H₅OH
D) Br₂ and PF₃
E) NH₃ and CH₃OH

Question 27

Choose the substance with the highest viscosity in the liquid phase.

A) (CH₃CH₂)₂CO
B) C₂H₄Cl₂
C) HOCH₂CH₂CH₂CH₂OH
D) CF₄
E) C₆H₁₄

Question 28

Which substance below has the strongest intermolecular forces?

A) A₂X, Δ_vapH = 39.6 kJ mol^-1
B) BY₂, Δ_vapH = 26.7 kJ mol^-1
C) C₃X₂, Δ_vapH = 36.4 kJ mol^-1
D) DX₂, Δ_vapH = 23.3 kJ mol^-1
E) EY₃, Δ_vapH = 21.5 kJ mol^-1

Question 29

Give the term for the temperature at which the gas and liquid phases form a supercritical fluid.

A) absolute temperature
B) definite temperature
C) fluid temperature
D) critical temperature
E) solid temperature

Question 30

Identify the substance with the highest viscosity in the liquid phase.

A) gasoline
B) water
C) corn syrup
D) motor oil
E) tea

Question 31

Choose the substance with the lowest viscosity in the liquid phase.

A) Cl₃CCCl₃
B) Cl₂CHCH₂Cl
C) Cl₂CHCHCl₂
D) ClCH₂CH₂Cl
E) Cl₃CCHCl₂

Question 32

Choose the substance with the highest viscosity in the liquid phase.

A) SbCl₃
B) AsCl₅
C) ICl₂
D) BeCl₂
E) OCl₂

Question 33

Which of the following statements is FALSE?

A) The rate of vaporization increases with increasing surface area.
B) The rate of vaporization increases with decreasing strength of intermolecular forces.
C) The rate of vaporization increases with increasing temperature.
D) Molecules with hydrogen bonding are more volatile than compounds with dipole-dipole forces.

Question 34

The energy required to increase the surface area of a liquid by a unit amount is called ________.

A) viscosity
B) surface tension
C) dipole-dipole force
D) hydrogen bonding
E) capillary action

Question 35

Place the following compounds in order of decreasing strength of intermolecular forces. I. CH₃CH₂CH₂CH₂CH₂CH₃ II. (CH₃)₃CCH₃ III. (CH₃)₃CCH₂CH₃

A) III > II > I
B) I > III > II
C) I > II > III
D) II > III > I
E) III > I > II

Question 36

Identify the term used to describe the ability of a liquid to flow against gravity up a narrow tube.

A) capillary action
B) viscosity
C) surface tension
D) density

Question 37

Choose the pair of substances that are most likely to form a homogeneous solution.

A) C₆H₁₄ and C₁₀H₂₀
B) LiBr and C₅H₁₂
C) N₂O₄ and NH₄Cl
D) C₆H₁₄ and H₂O
E) None of the pairs above will form a homogeneous solution.

Question 38

Which of the following statements is TRUE?

A) Vapour pressure increases with temperature.
B) Hydrogen bonds are stronger than covalent bonds.
C) Intermolecular forces hold the atoms in molecules together.
D) Dispersion forces are generally stronger than dipole-dipole forces.

Question 39

Choose the substance with the highest vapour pressure at a given temperature.

A) SiS₂
B) RbCl
C) CH₃SCH₃
D) BF₃
E) SbH₃

Question 40

Identify the compound that does not have hydrogen bonding.

A) (CH₃)₃N
B) H₂O
C) CH₃OH
D) HF
E) CH₃NH₂

Question 41

Place the following substances in order of decreasing vapour pressure at a given temperature. PF₅ BrF₃ CF₄

A) BrF₃ > PF₅ > CF₄
B) BrF₃ > CF₄ > PF₅
C) PF₅ > BrF₃ > CF₄
D) CF₄ > BrF₃ > PF₅
E) CF₄ > PF₅ > BrF₃

Question 42

Place the following substances in order of increasing boiling point. CH₃CH₂OH Ar CH₃OCH₃

A) Ar < CH₃OCH₃ < CH₃CH₂OH
B) CH₃CH₂OH < Ar < CH₃OCH₃
C) CH₃CH₂OH < CH₃OCH₃ < Ar
D) CH₃OCH₃ < Ar < CH₃CH₂OH
E) Ar < CH₃CH₂OH < CH₃OCH₃

Question 43

Choose the substance with the highest boiling point.

A) Acetone
B) Ethanol
C) Methanol
D) Propanol
E) Butanol

Question 44

Choose the substance with the lowest boiling point.

A) H₂S
B) NBr₃
C) F₂
D) CF₂H₂
E) H₂O₂

Question 45

Choose the substance with the lowest boiling point.

A) Acetone
B) Ethanol
C) Methanol
D) Propanol
E) Butanol

Question 46

Choose the substance with the highest boiling point.

A) CH₄
B) KI
C) CS₂
D) HF
E) I₂

Question 47

Place the following substances in order of decreasing vapour pressure at a given temperature. BeF₂ CH₃OH OF₂

A) CH₃OH > OF₂ > BeF₂
B) BeF₂ > OF₂ > CH₃OH
C) OF₂ > CH₃OH > BeF₂
D) OF₂ > BeF₂ > CH₃OH
E) BeF₂ > CH₃OH > OF₂

Question 48

Which of the following substances would you predict to have the highest Δ_vapH?

A) CH₃Cl
B) HCl
C) HOCH₂CH₂OH
D) CH₃CH₂OH
E) CH₃CH₂CH₂CH₃

Question 49

Place the following substances in order of decreasing boiling point. N₂ O₂ H₂

A) O₂ > H₂ > N₂
B) N₂ > H₂ > O₂
C) N₂ > O₂ > H₂
D) O₂ > N₂ > H₂
E) H₂ > N₂ > O₂

Question 50

Choose the substance with the lowest boiling point.

A) Diethyl ether
B) Ethanol
C) Methanol
D) Propanol
E) Butanol

Question 51

Place the following substances in order of decreasing boiling point. H₂O N₂ CO

A) CO > H₂O > N₂
B) N₂ > CO > H₂O
C) H₂O > CO > N₂
D) CO > N₂ > H₂O
E) N₂ > H₂O > CO

Question 52

How much energy is required to vaporize 158 g of butane (C₄H₁₀) at its boiling point if its Δ_vapH is 24.3 kJ mol^-1?

A) 15.1 kJ
B) 66.1 kJ
C) 89.4 kJ
D) 11.2 kJ
E) 38.4 kJ

Question 53

Place the following substances in order of increasing vapour pressure at a given temperature. NF₃ NH₃ BCl₃

A) NH₃ < NF₃ < BCl₃
B) NF₃ < NH₃ < BCl₃
C) BCl₃ < NF₃ < NH₃
D) NH₃ < BCl₃ < NF₃
E) BCl₃ < NH₃ < NF₃

Question 54

Choose the substance with the highest boiling point.

A) CH₄
B) CH₃CH₃
C) CH₃CH₂Cl
D) CH₃CH₂CH₂OH
E) H₂

Question 55

How much energy is required to vaporize 98.6 g of ethanol (C₂H₅OH) at its boiling point if its Δ_vapH is 40.5 kJ mol^-1?

A) 86.7 kJ
B) 11.5 kJ
C) 18.9 kJ
D) 52.8 kJ
E) 39.9 kJ

Question 56

Place the following substances in order of increasing vapour pressure at a given temperature. SF₆ SiH₄ SF₄

A) SF₆ < SiH₄ < SF₄
B) SiH₄ < SF₄ < SF₆
C) SF₆ < SF₄ < SiH₄
D) SF₄ < SF₆ < SiH₄
E) SiH₄ < SF₆ < SF₄

Question 57

Choose the substance with the lowest vapour pressure at a given temperature.

A) CO₂
B) BeCl₂
C) BF₃
D) He
E) PF₅

Question 58

How much energy is required to vaporize 48.7 g of dichloromethane (CH₂Cl₂) at its boiling point if its Δ_vapH is 31.6 kJ mol^-1?

A) 31.2 kJ
B) 6.49 kJ
C) 55.1 kJ
D) 15.4 kJ
E) 18.1 kJ

Question 59

Which of the following substances would you predict to have the highest Δ_vapH?

A) Xe
B) C₆H₆
C) SiF₄
D) Br₂
E) N₂

Question 60

Place the following substances in order of increasing boiling point. Ne Cl₂ O₂

A) Ne < Cl₂ < O₂
B) Cl₂ < O₂ < Ne
C) O₂ < Cl₂ < Ne
D) Cl₂ < Ne < O₂
E) Ne < O₂ < Cl₂

Question 61

Place the following substances in order of decreasing boiling point. He Ar H₂

A) He > H₂ > Ar
B) H₂ > He > Ar
C) He > Ar > H₂
D) Ar > He > H₂
E) H₂ > Ar > He

Question 62

How much energy is required to heat 36.0 g H₂O from a liquid at 65 °C to a gas at 115 °C? The following physical data may be useful: Δ_vapH = 40.7 kJ mol^-1
C_liq = 4.18 J g^-1 °C^-1
C_gas = 2.01 J g^-1 °C^-1
C_sol = 2.09 J g^-1 °C^-1
T_melting = 0 ^∘C
T_boiling = 100 ^∘C

A) 63.5 kJ
B) 87.7 kJ
C) 10.9 kJ
D) 52.7 kJ
E) 91.7 kJ

Question 63

Determine the vapour pressure (in mbar) of a substance at 36 °C whose normal boiling point is 84 °C and has a Δ_vapH of 22.1 kJ mol^-1.

A) 319 mbar
B) 31.8 mbar
C) 41.8 mbar
D) 147 mbar
E) 98 mbar

Question 64

Determine the normal boiling point of a substance whose vapour pressure is 73.46 mbar at 35 °C and has a Δ_vapH of 32.1 kJ mol^-1.

A) 255 K
B) 368 K
C) 412 K
D) 390. K
E) 466 K

Question 65

The normal boiling point of water is ________.

A) 0 °C
B) 32 °C
C) 212 °C
D) 100 °C
E) 273 °C

Question 66

The melting point of water is ________.

A) 0 °C
B) 32 °C
C) 212 °C
D) 100 °C
E) 273 °C

Question 67

The freezing point of water is ________.

A) 0 °C
B) 32 °C
C) 212 °C
D) 100 °C
E) 273 °C

Question 68

Define freezing.

A) the phase transition from solid to gas
B) the phase transition from gas to solid
C) the phase transition from gas to liquid
D) the phase transition from liquid to gas
E) the phase transition from liquid to solid

Question 69

Determine Δ_vapH for a compound that has a measured vapour pressure of 32.40 mbar at 273 K and 180.0 mbar at 325 K.

A) 41 kJ mol^-1
B) 79 kJ mol^-1
C) 24 kJ mol^-1
D) 13 kJ mol^-1
E) 34 kJ mol^-1

Question 70

Determine the vapour pressure (in mbar) of a substance at 29 °C, whose normal boiling point is 76 °C and has a Δ_vapH of 38.7 kJ mol^-1.

A) 80 mbar
B) 13 mbar
C) 21 mbar
D) 48 mbar
E) 128 mbar

Question 71

How much energy must be removed from a 125 g sample of benzene (molar mass = 78.11 g mol^-1) at 425.0 K to liquify the sample and lower the temperature to 335.0 K? The following physical data may be useful: Δ_vapH = 33.9 kJ mol^-1
Δ_fusH = 9.8 kJ mol^-1
C_liq = 1.73 J g^-1 °C^-1
C_gas = 1.06 J g^-1 °C^-1
C_sol = 1.51 J g^-1 °C^-1
T_melting = 279.0 K
T_boiling = 353.0 K

A) 38.9 kJ
B) 95.4 kJ
C) 67.7 kJ
D) 54.3 kJ
E) 74.4 kJ

Question 72

How much energy must be removed from a 94.4 g sample of benzene (molar mass = 78.11 g mol^-1) at 322.0 K to solidify the sample and lower the temperature to 205.0 K? The following physical data may be useful: Δ_vapH = 33.9 kJ mol^-1
Δ_fusH = 9.8 kJ mol^-1
C_liq = 1.73 J g^-1 °C^-1
C_gas = 1.06 J g^-1 °C^-1
C_sol = 1.51 J g^-1 °C^-1
T_melting = 279.0 K
T_boiling = 353.0 K

A) 17.6 kJ
B) 11.8 kJ
C) 70.2 kJ
D) 10.5 kJ
E) 29.4 kJ

Question 73

Define sublimation.

A) the phase transition from solid to gas
B) the phase transition from gas to solid
C) the phase transition from gas to liquid
D) the phase transition from liquid to gas
E) the phase transition from liquid to solid

Question 74

Consider the phase diagram shown. Choose the statement below that is TRUE.

A) The triple point of this substance occurs at a temperature of 31 °C.
B) At 10 bar of pressure, there is no temperature where the liquid phase of this substance would exist.
C) The solid phase of this substance is higher in density than the liquid phase.
D) The line separating the solid and liquid phases represents the Δ_vapH.

Question 75

Assign the appropriate labels to the phase diagram shown below.

A) A = liquid, B = solid, C = gas, D = critical point
B) A = gas, B = solid, C = liquid, D = triple point
C) A = gas, B = liquid, C = solid, D = critical point
D) A = solid, B = gas, C = liquid, D = supercritical fluid
E) A = liquid, B = gas, C = solid, D = triple point

Question 76

Identify triple point.

A) the temperature, pressure, and density for a gas
B) the temperature at which the boiling point equals the melting point
C) the temperature and pressure where liquid, solid, and gas are equally stable and are in equilibrium
D) the temperature that is unique for a substance
E) the temperature at which the solid and liquid coexist

Question 77

At atmospheric pressure, dry ice ________.

A) freezes
B) deposits
C) sublimes
D) melts
E) boils

Question 78

Define deposition.

A) A liquid becomes a gas.
B) A gas becomes a liquid.
C) A gas becomes a solid.
D) A solid becomes a gas.
E) A solid becomes a liquid.

Question 79

Consider the phase diagram below. If the dashed line at 1 atm of pressure is followed from 100 to 500 °C, what phase changes will occur (in order of increasing temperature)?

A) condensation followed by vaporization
B) sublimation followed by deposition
C) vaporization followed by deposition
D) fusion followed by vaporization
E) No phase change will occur under the conditions specified.

Question 80

How much energy is required to heat 87.1 g acetone (molar mass = 58.08 g mol^-1) from a solid at -154.0 °C to a liquid at -42. 0°C? The following physical data may be useful: Δ_fusH = 7.27 kJ mol^-1
C_liq = 2.16 J g^-1 °C^-1
C_gas = 1.29 J g^-1 °C^-1
C_sol = 1.65 J g^-1 °C^-1
T_melting = -95.0 °C

A) 8.48 kJ
B) 18.5 kJ
C) 32.2 kJ
D) 29.4 kJ
E) 9.97 kJ