Deck 11: Liquids,solids,and Intermolecular Forces

Question 1

For automobile engines,identify the best choice of motor oil.

A) high SAE for Maine in the winter and low SAE for Florida in the summer
B) low SAE for Maine in the winter and low SAE for Florida in the summer
C) high SAE for Maine in the winter and high SAE for Florida in the summer
D) low SAE for Maine in the winter and high SAE for Florida in the summer
E) It does not matter what the rating is for the motor oil.

Answer 1

low SAE for Maine in the winter and high SAE for Florida in the summer

Question 2

In DNA,adenine and thymine have ________ hydrogen bonds between them.

A) 4
B) 0
C) 1
D) 3
E) 2

Answer 2

2

Question 3

Identify the compound with the highest dipole moment.

A) CH₃OCH₃
B) CH₃CH₂CH₃
C) CH₃CHO
D) (CH₃)₂O
E) CH₃CN

Answer 3

CH₃CN

Question 4

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

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

Question 5

The two strands in DNA are held together by

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

Question 6

Which one of the following has a low density?

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

Question 7

Identify the characteristics of a liquid.

A) indefinite shape and volume
B) indefinite shape, but definite volume
C) definite shape and volume
D) none of the above
E) all of the above

Question 8

A paper clip floating on the top of water is an example of

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

Question 9

Identify the characteristics of a gas.

A) indefinite shape and volume
B) indefinite shape, but definite volume
C) definite shape and volume
D) none of the above
E) all of the above

Question 10

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 11

Identify the compound with the lowest boiling point.

A) CH₃OCH₃
B) CH₃CH₂CH₃
C) CH₃CHO
D) (CH₃)₂O
E) CH₃CN

Question 12

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 13

A molecule contains hydrogen bonding if it contains hydrogen covalently bonded to

A) fluorine, oxygen, or nitrogen.
B) chlorine, fluorine, or iodine.
C) sulfur, oxygen, or fluorine.
D) oxygen or nitrogen.
E) nitrogen, fluorine, oxygen, or nitrogen.

Question 14

The forces between polar molecules are known as

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

Question 15

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
E) none of the above

Question 16

Which of the following statements is TRUE?

A) Intermolecular forces are generally stronger than bonding forces.
B) The potential energy of molecules decreases 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 17

In DNA,cytosine and guanine hydrogen bond to each other with ________ hydrogen bonds.

A) 4
B) 0
C) 1
D) 3
E) 2

Question 18

In a liquid,the energy required to increase the surface of the area by a unit amount is called

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

Question 19

Identify the state of matter that is the most compressible.

A) gas
B) solid
C) liquid
D) All are compressible.
E) None is compressible.

Question 20

Explain why ice floats in water.

A) Ice is more dense than water.
B) Steam is less dense than water.
C) Ice is less dense than water.
D) Steam is more dense than water.
E) Ice is the same density as water.

Question 21

Determine ΔH_vap for a compound that has a measured vapor pressure of 24.3 torr at 273 K and 135 torr at 325 K.

A) 41 kJ/mol
B) 79 kJ/mol
C) 24 kJ/mol
D) 13 kJ/mol
E) 34 kJ/mol

Question 22

Define vaporization.

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 23

Place the following substances in order of increasing vapor 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 24

Place the following substances in order of decreasing vapor 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 25

How much energy is required to vaporize 48.7 g of dichloromethane (CH₂Cl₂)at its boiling point,if its ΔH_vap is 31.6 kJ/mol?

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

Question 26

Determine the vapor pressure (in torr)of a substance at 36°C,whose normal boiling point is 84°C and has a ΔH_vap of 22.1 kJ/mol.

A) 239 torr
B) 31.8 torr
C) 41.8 torr
D) 147 torr
E) 98 torr

Question 27

Define condensation.

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

Question 28

Describe sweating in humans.

A) It is an endothermic reaction.
B) The sweat evaporates absorbing heat from the body.
C) The skin is cooled.
D) None of the above
E) All of the above

Question 29

Capillary action occurs because

A) cohesive forces are greater than adhesive forces.
B) adhesive forces equal adhesive forces.
C) adhesive forces are greater than cohesive forces.
D) surface tension is high.
E) surface tension is low.

Question 30

Place the following substances in order of increasing vapor 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 31

Which of the following statements is TRUE?

A) Vapor 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.
E) None of the above is true.

Question 32

How much energy is required to vaporize 98.6 g of ethanol (C₂H₅OH)at its boiling point,if its ΔH_vap is 40.5 kJ/mol?

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

Question 33

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 34

Determine the normal boiling point of a substance whose vapor pressure is 55.1 mm Hg at 35°C and has a ΔH_vap of 32.1 kJ/mol.

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

Question 35

Determine the vapor pressure (in mm Hg)of a substance at 29°C,whose normal boiling point is 76°C and has a ΔH_vap of 38.7 kJ/mol.

A) 80 mm Hg
B) 13 mm Hg
C) 21 mm Hg
D) 48 mm Hg
E) 96 mm Hg

Question 36

Place the following substances in order of decreasing vapor 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 37

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 38

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.
E) None of the above is false.

Question 39

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 40

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 41

How much energy must be removed from a 94.4 g sample of benzene (molar mass = 78.11 g/mol)at 322.0 K to solidify the sample and lower the temperature to 205.0 K? The following physical data may be useful.
ΔH_vap = 33.9 kJ/mol
ΔH_fus = 9.8 kJ/mol
C_liq = 1.73 J/g°C
C_gas = 1.06 J/g°C
C_sol = 1.51 J/g°C
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 42

Which has the smallest dipole-dipole forces?

A) CH₃CH₂Cl
B) HI
C) F₂
D) CO

Question 43

On a phase diagram,the vaporization curve is between

A) a solid and a gas.
B) a solid and a liquid.
C) a liquid and a gas.
D) two solids.
E) two liquids.

Question 44

On a phase diagram,the fusion curve is between

A) a solid and a gas.
B) a solid and a liquid.
C) a liquid and a gas.
D) two solids.
E) two liquids.

Question 45

Which is expected to have the largest dispersion forces?

A) C H₄
B) C₉H₂₀
C) F₂
D) Si H₄

Question 46

Which of the following compounds exhibits hydrogen bonding?

A) CH₃Br
B) HCl
C) CH₃SCH₃
D) CH₃OH

Question 47

At atmospheric pressure,ice

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

Question 48

Define fusion.

A) the phase transition from solid to liquid
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 49

At atmospheric pressure,dry ice

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

Question 50

How much energy is required to heat 87.1 g acetone (molar mass = 58.08 g/mol)from a solid at -154.0°C to a liquid at -42.0°C? The following physical data may be useful. ΔH_fus = 7.27 kJ/mol
C_liq = 2.16 J/g°C
C_gas = 1.29 J/g°C
C_sol = 1.65 J/g°C
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

Question 51

Fresh vegetables with high water content do not freeze well.Explain.

A) Water expands when it freezes and damages the cell wall.
B) Water contracts when it freezes and damages the cell wall.
C) Water expands when it freezes and does not damage the cell wall.
D) Water contracts when it freezes and does not damage the cell wall.
E) Water does not change in size when it freezes.

Question 52

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

A) Cl₂
B) CO
C) HBr
D) NaCl
E) All of these have intermolecular forces stronger than dispersion.

Question 53

Define critical point.

A) The temperature and pressure above which a supercritical fluid exists.
B) The temperature and pressure where liquid, solid, and gas are equally stable and are in equilibrium.
C) The temperature and pressure below which a supercritical fluid exists.
D) The temperature and pressure are equal.
E) The temperature and pressure are not equal.

Question 54

Why is water an extraordinary substance?

A) Water has a low molar mass, yet it is a liquid at room temperature.
B) Water is the main solvent within living organisms.
C) Water has an exceptionally high specific heat capacity.
D) Water has strong hydrogen bonding.
E) All of the above.

Question 55

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

A) CH₂I₂
B) CH₃OCH₃
C) CH₃Cl
D) HCBr₃
E) CO₂

Question 56

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. ΔH_vap = 40.7 kJ/mol
C_liq = 4.18 J/g^∘C
C_gas = 2.01 J/g^∘C
C_sol = 2.09 J/g^∘C
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 57

On a phase diagram,the sublimation curve is between

A) a solid and a gas.
B) a solid and a liquid.
C) a liquid and a gas.
D) two solids.
E) two liquids.

Question 58

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

A) N₂
B) SO₂
C) H₂O
D) CBr₄
E) BCl₃

Question 59

How much energy must be removed from a 125 g sample of benzene (molar mass = 78.11 g/mol)at 425.0 K to liquify the sample and lower the temperature to 335.0 K? The following physical data may be useful.
ΔH_vap = 33.9 kJ/mol
ΔH_fus = 9.8 kJ/mol
C_liq = 1.73 J/g°C
C_gas = 1.06 J/g°C
C_sol = 1.51 J/g°C
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 60

Which of the following compounds exhibits dipole-dipole forces as its strongest attraction between molecules?

A) H₂
B) HBr
C) CO₂
D) CH₃NH₂
E) Kr

Question 61

What is the strongest type of intermolecular force present in F₂?

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

Question 62

What is the strongest type of intermolecular force present in CH₃(CH₂)₄OH?

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

Question 63

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

A) CI₄
B) C₂H₆
C) CH₃OH
D) CH₂Cl₂
E) None of the above compounds exhibits hydrogen bonding.

Question 64

What is the strongest type of intermolecular force present in CHCl₃?

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

Question 65

What type of intermolecular force causes the dissolution of CaCl₂ in water?

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

Question 66

Place the following compounds in order of increasing boiling point. LiF N₂ CH₃CH₂NH₂

A) NH₂CH₃ < LiF < N₂
B) N₂ < NH₂CH₃ < LiF
C) NH₂CH₃ < N₂ < LiF
D) N₂ < LiF < NH₂CH₃
E) LiF < NH₂CH₃ < N₂

Question 67

Choose the substance with the highest surface tension.

A) HOCH₂CH₂OH
B) CH₂F₂
C) CH₃CH₂I
D) CH₃CH₂CH₂OH
E) CH₃CH₂CH₃

Question 68

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

A) CBr₄ and SF₂
B) NF₃ and SO₂
C) CO and C₆H₁₄
D) NH₂CH₃ and CH₄
E) None of the pairs above will form a homogeneous solution.

Question 69

Choose the substance with the highest viscosity.

A) (CH₃CH₂)₂CO
B) C₂H₄Br₂
C) HOCH₂CH₂CH₂CH₂OH
D) CI₄
E) C₈H₁₈

Question 70

Choose the substance with the lowest surface tension.

A) CH₃SeCH₂CH₃
B) CH₃CH₂CH₂CH₃
C) C₆H₆
D) H₂Se
E) (CH₃)₂SO

Question 71

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

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

Question 72

The normal boiling point for H Br is higher than the normal boiling point for H Cl.This can be explained by

A) larger dipole-dipole forces for H Br .
B) larger dispersion forces for H Br .
C) larger hydrogen-bond forces for H Br .
D) larger dipole-dipole forces, larger dispersion forces, and larger hydrogen-bond forces for H Br .

Question 73

How many compounds,of the ones listed below,have hydrogen bonding? CH₃(CH₂)₂NH₂ CH₃(CH₂)₂NH(CH₂)₄CH₃ (CH₃CH₂)₂N(CH₂)₄CH₃

A) 2
B) 3
C) 1
D) 0

Question 74

In liquid methanol, CH₃OH
Which intermolecular forces are present?

A) Dispersion, hydrogen bonding and dipole-dipole forces are present.
B) Only dipole-dipole and hydrogen bonding forces are present.
C) Only dispersion and ion-dipole forces are present.
D) Only hydrogen bonding forces are present.

Question 75

Place the following compounds in order of decreasing strength of intermolecular forces. HF F₂ CO₂

A) HF > CO₂ > F₂
B) HF > F₂ > CO₂
C) F₂ > CO₂ > HF
D) CO₂ > HF > F₂
E) CO₂ > F₂ > HF

Question 76

Identify the compound that has hydrogen bonding.

A) (CH₃)₃N
B) Cl₂
C) CH₃CH₃
D) HI
E) H₂O

Question 77

List the compounds in order of decreasing boiling point. CH₃O CH₃ Rn CH₃CHO

A) CH₃O CH₃ > CH₃CHO > Rn
B) Rn > CH₃O CH₃ > CH₃CHO
C) CH₃O CH₃ > Rn > CH₃CHO
D) CH₃CHO > CH₃O CH₃ > Rn
E) Rn > CH₃CHO > CH₃O CH₃

Question 78

Place the following compounds in order of increasing strength of intermolecular forces. CH₄ CH₃(CH₂)₃CH₃ CH₃CH₃

A) CH₃(CH₂)₃CH₃ < CH₄ < CH₃CH₃
B) CH₃(CH₂)₃CH₃ < CH₃CH₃ < CH₄
C) CH₃CH₃ < CH₄ < CH₃(CH₂)₃CH₃
D) CH₄ < CH₃(CH₂)₃CH₃ < CH₃CH₃
E) CH₄ < CH₃CH₃ < CH₃(CH₂)₃CH₃

Question 79

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

A) KCl and Hg
B) NaI and C₆H₁₄
C) C₃H₈ and C₂H₅OH
D) F₂ and PF₃
E) NH₃ and CH₃OH

Question 80

Identify the compound that does NOT have hydrogen bonding.

A) (CH₃)₂N(CH₂)₃CH₃
B) H₂O
C) CH₃(CH₂)₅
D) HF
E) CH₃(CH₂)₂NH₂