Deck 11: States of Matter; Liquids and Solids

Question 1

The boiling point of a liquid is

A)always the temperature at which the vapor pressure equals 760 mmHg (1 atm).
B)always the temperature at which the liquid phase of a substance is in equilibrium with the vapor phase.
C)always the temperature at which the vapor pressure equals the pressure exerted on the liquid.
D)always equal to the vapor pressure of the liquid at a given temperature.
E)independent of the pressure exerted on the liquid.

Answer 1

always the temperature at which the vapor pressure equals the pressure exerted on the liquid.

Question 2

Which of the following involves a change in temperature during the phase transition?

A)condensation of water
B)liquifaction of ammonia
C)fusion of ethanol
D)all of the above
E)none of the above

Answer 2

none of the above

Question 3

Assume 12,500 J of energy is added to 2.0 moles (36 grams)of H₂O as an ice sample at 0°C.The molar heat of fusion is 6.02 kJ/mol.The specific heat of liquid water is 4.18 J/g °C.The molar heat of vaporization is 40.6 kJ/mol.The resulting sample contains which of the following?

A)water and water vapor
B)ice and water
C)only water
D)only water vapor
E)only ice

Answer 3

only water

Question 4

The process represented by the equation C₁₀H₈(s)→ C₁₀H₈(g)is

A)melting.
B)liquefaction.
C)sublimation.
D)condensation.
E)fusion.

Question 5

The vapor pressure of a given liquid will increase if

A)the liquid is moved to a container in which its surface is very much larger.
B)the volume of the liquid is increased.
C)the temperature is increased.
D)the volume of the vapor phase is increased.
E)a more volatile liquid is added to the given liquid.

Question 6

A particular compound has an enthalpy of vaporization of 28400 J/mol.At 274 K it has a vapor pressure of 122 mmHg.What is its vapor pressure at 311 K? (R = 8.31 J/(K· mol))

A)117 mmHg
B)262 mmHg
C)27.6 mmHg
D)538 mmHg
E)126 mmHg

Question 7

A liquid has an enthalpy of vaporization of 29.1 kJ/mol.At 274 K it has a vapor pressure of 103 mmHg.What is the normal boiling point of this liquid? (R = 8.31 J/(K· mol))

A)294 K
B)325 K
C)274 K
D)257 K
E)237 K

Question 8

In a certain mountain range,water boils at 94°C.What is the atmospheric pressure under these conditions? The enthalpy of vaporization of water at 100°C is 40.7 kJ/mol.(R = 8.31 J/(K · mol))

A)1750 mmHg
B)324 mmHg
C)613 mmHg
D)941 mmHg
E)329 mmHg

Question 9

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

A)fusion.
B)condensation.
C)melting.
D)vaporization.
E)sublimation.

Question 10

In which of the following processes will energy be evolved as heat?

A)crystallization
B)melting
C)sublimation
D)vaporization
E)none of these

Question 11

Which of the following processes is exothermic?

A)condensation of water
B)fusion of ethanol
C)vaporization of water
D)evaporation of ammonia
E)sublimation of carbon dioxide

Question 12

What is the name for the following phase change?
I₂(l)→ I₂(g)

A)vaporization
B)freezing
C)condensation
D)sublimation
E)melting

Question 13

A bottle is filled with a small amount of a volatile liquid and sealed.Sometime later it is observed that no liquid is evident in the sealed bottle.Which of the following statements would explain this observation?

A)More time is needed to establish equilibrium.
B)Liquid and vapor are at equilibrium in the bottle.
C)Too little liquid was added to achieve a liquid vapor equilibrium in the closed system.
D)The vapor state is favored when equilibrium is established.
E)The liquid has undergone sublimation.

Question 14

If more ice is added to an ice-water mixture at equilibrium,

A)the temperature will increase somewhat.
B)the vapor pressure of the water will decrease.
C)the temperature will decrease somewhat.
D)the vapor pressure of the water will rise.
E)the vapor pressure of the water will remain constant.

Question 15

The vapor pressure of a liquid increases with increasing temperature.Which of the following statements best explains this relationship?

A)All the molecules have greater kinetic energies.
B)The number of gaseous molecules above the liquid remains constant,but these molecules have greater average kinetic energy.
C)The faster-moving molecules in the liquid exert a greater pressure.
D)The intermolecular forces between the molecules decrease at higher temperatures.
E)The average kinetic energy of molecules is greater; thus more molecules can enter the gaseous state.

Question 16

What is the value of q when 8.29 g of water vaporizes at 373 K? The enthalpy of condensation of water at 373 K is -40.7 kJ/mol.

A)-337 kJ
B)-18.7 kJ
C)18.7 kJ
D)337 kJ
E)0.203 kJ

Question 17

Which of the following phase changes are endothermic?

A)sublimation
B)condensation
C)deposition
D)liquifaction
E)crystallization

Question 18

The enthalpy of fusion of aluminum is 10.7 kJ/mol.How many grams of aluminum can be melted by adding 81.4 kJ of energy to the metal at its melting point?

A) g
B)32.2g
C)3.01 g
D)7.6 g
E) g

Question 19

Which of the following statements concerning liquids is incorrect?

A)The volume of a liquid changes very little with pressure.
B)Liquids are relatively incompressible.
C)Liquid molecules move slowly compared to solids.
D)Non-volatile liquids have low vapor pressures at room temperature.
E)The molecules of a liquid are in constant random motion.

Question 20

How much heat is released at constant pressure if a 15.0-L tank containing 47.0 atm of hydrogen sulfide gas condenses at its boiling point of -60.0^oC? The enthalpy of vaporization of hydrogen sulfide is 18.7 kJ/mol at -60.0^oC.(R = 0.0821 L • atm/(K • mol))

A)1.31 × 10² J
B)2.68 × 10⁶ J
C)4.64× 10² J
D)1.87× 10⁴ J
E)7.54 × 10⁵ J

Question 21

Which explanation best describes surface tension?

A)Molecules at the surface of a liquid experience a net force towards the liquid's interior.
B)Molecules at the edges of a liquid adhere to the surface of the liquid's container.
C)Molecules of a liquid tend to form a concave meniscus.
D)Molecules of a liquid tend to resist flow.
E)Molecules of a liquid have a very low vapor pressure.

Question 22

From a consideration of the phase diagram below,a change from point M to point N corresponds to

A)sublimation.
B)liquefaction.
C)evaporation.
D)condensation.
E)freezing.

Question 23

The critical point of CCl₄ is 283°C and 45 atm pressure.Liquid CCl₄ has a vapor pressure of 10.0 atm at 178°C.Which of the following statements must be true?

A)Vapor and liquid can only be in equilibrium at one temperature-the normal boiling point.
B)Liquid CCl₄ can exist at temperatures greater than 283°C if the pressure is greater than 45 atm.
C)Liquid and solid can only be in equilibrium at one temperature-the freezing point.
D)The triple point of CCl₄ must be less than 178°C.
E)The normal boiling point of CCl₄ must be greater than 178°C.

Question 24

The triple point of iodine is at 90 torr and 115°C.This means that liquid I₂

A)cannot have a vapor pressure less than 90 torr.
B)is more dense than I₂(s).
C)cannot exist at 1 atmosphere pressure.
D)cannot exist above 115°C.
E)can exist at pressure of 10 torr.

Question 25

Choose the correct statement about the diagram below.

A)The diagram shows the triple point above 1 atm pressure.
B)The diagram is qualitatively correct for water.
C)The diagram shows that the melting point of the solid increases with increasing pressure.
D)The diagram could represent the phase diagram of CO₂.
E)None of the above statements is correct.

Question 26

In which of the following substances are intermolecular forces of attraction absent?

A)HF(l)
B)CCl₄(l)
C)NaCl(l)
D)H₂O(l)
E)N₂(l)

Question 27

If the liquid of a pure substance has a lower density than the solid,what is the effect on the pressure-temperature phase diagram?

A)The vapor-pressure curve arches upward.
B)The normal melting point is above room temperature.
C)The melting-point curve has a negative slope.
D)The vapor-pressure curve arches downward.
E)The melting-point curve has a positive slope.

Question 28

If the diameter of a spherical water droplet is 100.0 μm,how much energy is required to increase the diameter of the water droplet by 5.0 μm? The surface tension of water is 1.0 × 10^-3 J/m².

A)3.1 × 10^-11 J
B)3 × 10^-12 J
C)7.9 × 10^-14 J
D)1 × 10^-11 J
E)4 × 10^-11 J

Question 29

What is the enthalpy of vaporization of a compound that has a vapor pressure of 151 mmHg at 247 K and 1.52 mmHg at 187 K? (R = 8.31 J/(K· mol))

A)636 kJ/mol
B)2 kJ/mol
C)4 kJ/mol
D)29 kJ/mol
E)290 kJ/mol

Question 30

Which of the following statements concerning the accompanying phase diagram is false?

A)The solid is more dense than the liquid.
B)Point C is the critical point of the substance.
C)Point A is the triple point of the substance.
D)The normal boiling point is above the triple point.
E)The curve AD divides the solid region from the gas region.

Question 31

Below is a phase diagram for a substance. Which line represents the melting-point curve of the substance?

A)R-X
B)S-X
C)X-Z
D)S-Z
E)M-N

Question 32

Below is a phase diagram for a substance. What is the name for point Z on the diagram?

A)normal boiling point.
B)critical point.
C)melting point.
D)boiling point.
E)triple point.

Question 33

Which is the best reason for why water in a glass capillary has a concave meniscus,while mercury in a glass capillary has a convex meniscus?

A)Mercury has a greater dispersion force than water.
B)The water is attracted more strongly to the glass than the mercury is attracted to the glass.
C)The mercury is attracted more strongly to the glass than the water is attracted to the glass.
D)Water is a molecular compound while mercury is a metallic element.
E)Water has a greater dispersion force than mercury.

Question 34

The measure of the resistance to flow of a liquid is

A)London forces.
B)van der Waals forces.
C)viscosity.
D)vapor pressure.
E)surface tension.

Question 35

Knowing that ΔH_vap for water is 40.7 kJ/mol,calculate P_vap of water at 37°C.

A)52.7 torr
B)25.4 torr
C)18.7 torr
D)12.4 torr
E)6.90 torr

Question 36

For a particular liquid,raising its temperature from 339 K to 365 K causes its vapor pressure to double.What is the enthalpy of vaporization of this liquid? (R = 8.31 J/(K · mol))

A)27 kJ/mol
B)221 kJ/mol
C)3 kJ/mol
D)307 kJ/mol
E)149 kJ/mol

Question 37

Below is a phase diagram for a substance. Which line represents the vapor-pressure curve of the substance?

A)S-Z
B)X-Z
C)S-X
D)M-N
E)R-X

Question 38

Below is a phase diagram for a substance. What is the name for point X on the diagram?

A)boiling point
B)normal boiling point
C)triple point
D)melting point
E)critical point

Question 39

Given the accompanying phase diagram,under what conditions will solid be found in equilibrium with either liquid or gas?

A)Anywhere along curve AB.
B)Anywhere along curve AC.
C)Anywhere along curve AD.
D)Anywhere along curve AB and AD.
E)Anywhere along curve AC and AD.

Question 40

In the accompanying phase diagram,a liquid can be present at combinations of temperature and pressure corresponding to points

A)A,C,G,and D.
B)A,C,D,and F.
C)A,B,C,and G.
D)A and C only.
E)G,C,D,and E.

Question 41

Which of the following indicates the existence of strong intermolecular forces of attraction in a liquid?

A)a very low critical temperature
B)a very low boiling point
C)a very low vapor pressure
D)a very low viscosity
E)a very low enthalpy of vaporization

Question 42

Which of the following pure substances has the highest normal boiling point?

A)HI
B)HCl
C)HF
D)H₂S
E)HBr

Question 43

Which compound has the lowest standard enthalpy of vaporization at 25°C?

A)C₆H₁₄
B)C₈H₁₆
C)C₅H₁₂
D)C₈H₁₈
E)C₇H₁₆

Question 44

Which of the following pure substances has an unusually high normal boiling point?

A)CH₃OCH₃
B)CH₃SH
C)HCl
D)CH₃NH₂
E)CH₃Cl

Question 45

In an experiment,40.0 mmol of helium gas is collected over water.The total volume of gas collected is 0.224 L.Under similar conditions,the gas is collected over two other liquids,A and B.The total volume of gas collected over A and B are 0.222 L and 0.227 L,respectively.Which of the following statements is false?

A)Liquid B boils at a higher temperature than water
B)Liquid A boils at a higher temperature than water
C)The vapor pressure of B is higher than that of A
D)The vapor pressure of B is higher than that of water
E)Liquid A boils at a temperature higher than B

Question 46

Which of the following pure substances has the highest standard enthalpy of vaporization at 25°C?

A)H₂O
B)NH₃
C)PH₃
D)AsH₃
E)SbH₃

Question 47

Which of the following compounds has the highest normal boiling point?

A)CH₃CH₂CH₂CH₃
B)CH₃Cl
C)CH₃CH₂OH
D)CH₃OCH₃
E)CH₃CH₂CH₃

Question 48

Which of the following pure substances has the lowest normal boiling point?

A)H₂S
B)NH₃
C)H₂O
D)H₂Te
E)H₂Se

Question 49

Rank the following molecules in order of increasing normal boiling point: CH₃CH₂OH,CH₃CH₂CH₂OH,CH₃CH₂OCH₃.

A)lowest CH₃CH₂CH₂OH,CH₃CH₂OCH₃,CH₃CH₂OH highest.
B)lowest CH₃CH₂OH,CH₃CH₂OCH₃,CH₃CH₂CH₂OH highest.
C)lowest CH₃CH₂CH₂OH,CH₃CH₂OH,CH₃CH₂OCH₃ highest.
D)lowest CH₃CH₂OCH₃,CH₃CH₂OH,CH₃CH₂CH₂OH highest.
E)lowest CH₃CH₂OCH₃,CH₃CH₂CH₂OH,CH₃CH₂OH highest.

Question 50

Why does hydrogen fluoride have an unusually high normal boiling point compared to the other hydrogen halides?

A)The H-F bond in hydrogen fluoride is very strong.
B)Hydrogen fluoride has very strong London dispersion forces.
C)Hydrogen fluoride is capable of forming hydrogen bonds.
D)Hydrogen fluoride is ionic.
E)Hydrogen fluoride is covalent.

Question 51

At 25°C,the vapor pressure of diethyl ether,(CH₃CH₂)₂O,is higher than the vapor pressure of its isomer n-butanol,CH₃CH₂CH₂CH₂OH,because

A)diethyl ether has a higher density than n-butanol.
B)diethyl ether has weaker intermolecular forces than n-butanol.
C)diethyl ether has a lower critical temperature than n-butanol.
D)diethyl ether has a higher surface tension than n-butanol.
E)diethyl ether has weaker intramolecular forces than n-butanol.

Question 52

When two water molecule form a hydrogen bond,which atoms are involved in the interaction?

A)Two hydrogens from one molecule and one hydrogen from the other molecule
B)An oxygen from one molecule and an oxygen from the other molecule
C)Two hydrogens from one molecule and one oxygen from the other molecule
D)A hydrogen from one molecule and a hydrogen from the other molecule
E)A hydrogen from one molecule and an oxygen from the other molecule

Question 53

Which of the following pure substances has the highest vapor pressure at room temperature?

A)Si₃H₈
B)Si₂H₆
C)Si₂Cl₆
D)Si₄H₁₀
E)SiH₄

Question 54

Sulfur trioxide (SO₃)is able to be liquefied at low temperatures due to which intermolecular force?

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

Question 55

Which of the following compounds has the highest vapor pressure at 25°C?

A)CH₃CH₂OH
B)CH₃CH₂CH₂CH₃
C)CH₃OCH₃
D)CH₃CH₂CH₃
E)CH₃CH₂CH₂Cl

Question 56

Which of the following compounds is expected to have the lowest vapor pressure?

A)CH₃OCH₃
B)CH₃CH₂F
C)CH₃CH₂OH
D)CH₃CH₂CH₂CH₃
E)CH₃CH₂CH₃

Question 57

Which of the following compounds has the lowest normal boiling point?

A)CH₃CH₂CH₂NH₂
B)CH₃CH₂CH₂F
C)CH₃CH₂CH₂OH
D)CH₃CH₂COOH
E)CH₃CH(OH)CH₃

Question 58

Rank the following in order of increasing normal boiling point: N₂,O₂,Br₂,Xe.

A)N₂ < O₂ < Xe < Br₂
B)O₂ < N₂ < Xe < Br₂
C)Br₂ < Xe < N₂ < O₂
D)N₂ < O₂ < Br₂ < Xe
E)Xe < Br₂ < N₂ < O₂

Question 59

Which one of the following decreases as the strength of the attractive intermolecular forces increases?

A)The normal boiling temperature.
B)The vapor pressure of a liquid.
C)The extent of deviations from the ideal gas law.
D)The heat of vaporization.
E)The sublimation temperature of a solid.

Question 60

Which of the following pure substances has the lowest vapor pressure at 25°C?

A)SbH₃
B)NH₃
C)PH₃
D)AsH₃
E)H₂O

Question 61

What is the maximum number of hydrogen bonds in which a water molecule could participate?

A)2
B)4
C)3
D)6
E)5

Question 62

Which of the following is not a covalent network solid?

A)diamond
B)silicon carbide
C)quartz
D)iron
E)graphite

Question 63

Which of the following pure substances may exhibit hydrogen bonding?

A)CH₃Cl
B)CH₃OCH₃
C)H₂CO
D)N(CH₃)₃
E)H₂NNH₂

Question 64

Which of the following pure substances has the highest normal melting point?

A)KF
B)KI
C)NaF
D)NaCl
E)NaI

Question 65

Which pure substance exhibits hydrogen bonding?

A)HNF₂
B)B₂H₆
C)HBr
D)H₂S
E)CaH₂

Question 66

The strongest intermolecular forces present in a sample of pure I₂ are

A)London forces.
B)dipole-dipole forces.
C)metallic bonds.
D)covalent network bonds.
E)covalent bonds.

Question 67

A solid has a very high melting point,is hard,and in the molten state is a non-conductor.The solid is most likely

A)a covalent network solid.
B)a metallic solid.
C)an amorphous solid.
D)a molecular solid.
E)an ionic solid.

Question 68

Which bonding interaction best describes the strongest intermolecular forces in AlH₃?

A)dipole-dipole forces
B)metallic bonding
C)ionic bonding
D)London dispersion forces
E)primarily hydrogen bonding

Question 69

Which of the following best describes silane (SiH₄)at room temperature and pressure?

A)ionic solid
B)covalent network solid
C)nonpolar molecular gas
D)polar molecular gas
E)metallic solid

Question 70

Which of the following is a molecular solid?

A)NaCl
B)CH₄
C)SiO₂
D)C(graphite)
E)C(diamond)

Question 71

Which of the following is an ionic solid?

A)SiO₂(s)
B)Ne(s)
C)Na(s)
D)CsF(s)
E)CO₂(s)

Question 72

Van der Waals forces must be broken to melt this type of solid.

A)A covalent network solid.
B)A metallic solid.
C)A molecular solid.
D)An ionic solid.
E)none of the above

Question 73

Which of the following is a molecular solid?

A)carborundum,SiC
B)quartz
C)glass
D)hydrogen chloride
E)potassium

Question 74

The strongest intermolecular forces between molecules of PH₃ are

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

Question 75

Which substance can be described as cations bonded together by mobile electrons?

A)S₈(s)
B)Ag(s)
C)HCl(l)
D)KCl(s)
E)Kr(l)

Question 76

Which of the following best describes carbon dioxide (CO₂)at room temperature and pressure?

A)ionic solid
B)nonpolar molecular gas
C)metallic solid
D)polar molecular gas
E)covalent network solid

Question 77

Which of the following is the strongest intermolecular force present in dry ice,CO₂(s)?

A)covalent bonding
B)hydrogen bonding
C)ionic bonding
D)London forces
E)metallic bonding

Question 78

Which of the following best describes calcium hydride (CaH₂)at room temperature and pressure?

A)nonpolar molecular gas
B)metallic solid
C)ionic solid
D)polar molecular gas
E)covalent network solid

Question 79

The molecules in a sample of solid SO₂ are attracted to each other by a combination of

A)H-bonding and ionic bonding.
B)covalent bonding and dipole-dipole interactions.
C)London forces and H-bonding.
D)London forces and dipole-dipole interactions.
E)none of these

Question 80

Which of the following substances has the weakest intermolecular forces?

A)I₂
B)C₈H₁₈
C)SiH₄
D)CH₃CH₂CH₂CH₂OH
E)SbCl₃