chemistry: a molecular approach, 2e...

Chemistry: A Molecular Approach, 2e (Tro)Chapter 11 Liquids, Solids, and Intermolecular Forces

Multiple Choice Questions

1) Identify the characteristics of a liquid.A) indefinite shape and volumeB) indefinite shape, but definite volumeC) definite shape and volumeD) none of the aboveE) all of the aboveAnswer: BDiff: 1 Page Ref: 11.2

2) Which one of the following has a low density?A) gasB) liquidC) solidD) none of the aboveE) all of the aboveAnswer: ADiff: 1 Page Ref: 11.2

3) Which one of the following has a definite shape and volume?A) gasB) liquidC) solidD) none of the aboveE) all of the aboveAnswer: CDiff: 1 Page Ref: 11.2

4) Give the change in condition to go from a liquid to a gas.A) increase heat or reduce pressureB) increase heat or increase pressureC) cool or reduce pressureD) cool or increase pressureE) none of the aboveAnswer: ADiff: 1 Page Ref: 11.2

5) The forces between polar molecules is known as __________.A) hydrogen bondingB) ion-dipole forcesC) dipole-dipole forcesD) dispersion forcesE) ionic forcesAnswer: CDiff: 1 Page Ref: 11.2

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6) 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 are true.Answer: BDiff: 1 Page Ref: 11.3

7) What is the strongest type of intermolecular force present in H2?A) ion-dipoleB) dipole-dipoleC) dispersionD) hydrogen bondingE) none of the aboveAnswer: CDiff: 1 Page Ref: 11.3

8) What is the strongest type of intermolecular force present in CHF3?A) ion-dipoleB) dispersionC) hydrogen bondingD) dipole-dipoleE) none of the aboveAnswer: DDiff: 1 Page Ref: 11.3

9) What is the strongest type of intermolecular force present in NH2CH3?A) dispersionB) dipole-dipoleC) hydrogen bondingD) ion-dipoleE) none of the aboveAnswer: CDiff: 1 Page Ref: 11.3

10) What type of intermolecular force causes the dissolution of NaCl in water?A) hydrogen bondingB) dipole-dipole forcesC) ion-dipole forceD) dispersion forcesE) none of the aboveAnswer: CDiff: 1 Page Ref: 11.3


11) Choose the molecule or compound that exhibits dispersion forces as its strongest intermolecular force.A) Cl2B) COC) HFD) NaClE) All of these have intermolecular forces stronger than dispersion.Answer: ADiff: 2 Page Ref: 11.3

12) Choose the molecule or compound that exhibits dipole-dipole forces as its strongest intermolecular force.A) H2B) SO2C) NH3D) CF4E) BCl3Answer: BDiff: 2 Page Ref: 11.3

13) Choose the compound that exhibits hydrogen bonding as its strongest intermolecular force.A) SCl2B) C2H6C) CH3OHD) CH2F2E) None of the above compounds exhibit hydrogen bonding.Answer: CDiff: 2 Page Ref: 11.3

14) Place the following compounds in order of increasing strength of intermolecular forces.

CO2 F2 NH2CH3

A) NH2CH3 < CO2 < F2B) F2 < NH2CH3 < CO2C) NH2CH3 < F2 < CO2D) F2 < CO2 < NH2CH3E) CO2 < NH2CH3 < F2Answer: DDiff: 2 Page Ref: 11.3


15) Place the following compounds in order of increasing strength of intermolecular forces.

CH4 CH3CH2CH3 CH3CH3

A) CH3CH2CH3 < CH4 < CH3CH3B) CH3CH2CH3 < CH3CH3 < CH4C) CH3CH3 < CH4 < CH3CH2CH3D) CH4 < CH3CH2CH3 < CH3CH3E) CH4 < CH3CH3 < CH3CH2CH3Answer: EDiff: 2 Page Ref: 11.3

16) Place the following compounds in order of decreasing strength of intermolecular forces.

HF O2 CO2

A) HF > CO2 > O2B) HF > O2 > CO2 C) O2 > CO2 > HFD) CO2 > HF > O2E) CO2 > O2 > HFAnswer: ADiff: 2 Page Ref: 11.3

17) Place the following compounds in order of decreasing strength of intermolecular forces.

I. CH3CH2CH2CH2CH2CH3 II. (CH3)3CCH3 III. (CH3)3CCH2CH3

A) III > II > IB) I > III > IIC) I > II > IIID) II > III > IE) III > I > IIAnswer: BDiff: 2 Page Ref: 11.3

18) Which has the smallest dipole-dipole forces? A) CH3Cl B) HBr C) O2D) NO Answer: CDiff: 2 Page Ref: 11.3


19) Which is expected to have the largest dispersion forces? A) C3H8B) C12H26C) F2D) Be Cl2Answer: BDiff: 2 Page Ref: 11.3

20) Identify the compound that does not have dipole-dipole forces as its strongest force.A) CH2Cl2B) CH3OCH3C) CH3BrD) HCCl3E) CO2Answer: EDiff: 2 Page Ref: 11.3

21) Which of the following compounds exhibits hydrogen bonding? A) CH3ClB) HI C) CH3OCH3 D) NH3 Answer: DDiff: 2 Page Ref: 11.3

22) Identify the compound that does not have hydrogen bonding.A) (CH3)3NB) H2OC) CH3OHD) HFE) CH3NH2Answer: ADiff: 2 Page Ref: 11.3

23) Choose the pair of substances that are most likely to form a homogeneous solution.A) NaCl and HgB) LiF and C6H14C) C3H8 and C2H5OHD) Br2 and PF3E) NH3 and CH3OHAnswer: EDiff: 2 Page Ref: 11.3


24) Choose the pair of substances that are most likely to form a homogeneous solution.A) C6H14 and C10H20B) LiBr and C5H12C) N2O4 and NH4ClD) C6H14 and H2OE) None of the pairs above will form a homogeneous solution.Answer: ADiff: 2 Page Ref: 11.3

25) Choose the pair of substances that are most likely to form a homogeneous solution.A) CCl4 and SCl2B) NF3 and SO2C) CO and C6H6D) NH2CH3 and CH4E) None of the pairs above will form a homogeneous solution.Answer: BDiff: 2 Page Ref: 11.3

26) In liquid propanol, CH3CH2CH2OH

which intermolecular forces are present? A) Dispersion, hydrogen bonding and dipole-dipole forces are present.B) Only dipole-dipole and ion-dipole forces are present.C) Only dispersion and dipole-dipole forces are present.D) Only hydrogen bonding forces are present.Answer: ADiff: 3 Page Ref: 11.3

27) Which of the following compounds exhibits only dispersion and dipole-dipole intermolecular interactions? A) H2B) HI C) CO2D) CH3NH2 Answer: BDiff: 3 Page Ref: 11.3

28) The normal boiling point for H2Se is higher than the normal boiling point for H2S . This can be explained byA) larger dipole-dipole forces for H2Se .B) larger dispersion forces for H2Se .C) larger hydrogen-bond forces for H2Se .D) larger dipole-dipole forces, larger dispersion forces, and larger hydrogen-bond forces for H2Se .Answer: BDiff: 3 Page Ref: 11.3


29) In a liquid, the energy required to increase the surface of the area by a unit amount is called __________.A) viscosityB) surface tensionC) dipole-dipole forceD) hydrogen bondingE) capillary actionAnswer: BDiff: 1 Page Ref: 11.4

30) Choose the substance with the highest surface tension.A) HOCH2CH2OHB) CH2F2C) CH3CH2FD) CH3CH2OHE) CH3CH2CH3Answer: ADiff: 2 Page Ref: 11.4

31) Choose the substance with the lowest surface tension.A) CH3SHB) CH3CH2CH2CH3C) C6H6D) H2OE) (CH3)2COAnswer: BDiff: 2 Page Ref: 11.4

32) Choose the substance with the highest viscosity.A) (CH3CH2)2COB) C2H4Cl2C) HOCH2CH2CH2CH2OHD) CF4E) C6H14Answer: CDiff: 2 Page Ref: 11.4

33) Choose the substance with the lowest viscosity.A) Cl3CCCl3B) Cl2CHCH2ClC) Cl2CHCHCl2D) ClCH2CH2ClE) Cl3CCHCl2Answer: DDiff: 2 Page Ref: 11.4


34) Choose the substance with the highest viscosity.A) SbCl3B) AsCl5C) ICl2D) BeCl2E) OCl2Answer: DDiff: 2 Page Ref: 11.4

35) Identify the substance with the highest viscosity.A) gasolineB) waterC) corn syrupD) motor oilE) teaAnswer: CDiff: 2 Page Ref: 11.4

36) Identify the term used to describe the ability of a liquid to flow against gravity up a narrow tube.A) capillary actionB) viscosityC) surface tensionD) densityE) none of the aboveAnswer: ADiff: 2 Page Ref: 11.4

37) 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 are true.Answer: ADiff: 1 Page Ref: 11.5

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 are false.Answer: DDiff: 1 Page Ref: 11.5


39) Which substance below has the strongest intermolecular forces?A) A2X, ΔHvap= 39.6 kJ/molB) BY2, ΔHvap= 26.7 kJ/molC) C3X2, ΔHvap= 36.4 kJ/molD) DX2, ΔHvap= 23.3 kJ/molE) EY3, ΔHvap= 21.5 kJ/molAnswer: ADiff: 1 Page Ref: 11.5

40) 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.Answer: ADiff: 1 Page Ref: 11.5

41) Give the term for the temperature at which the gas and liquid phases form a supercritical fluid.A) absolute temperatureB) definite temperatureC) fluid temperatureD) critical temperatureE) solid temperatureAnswer: DDiff: 1 Page Ref: 11.5

42) Choose the substance with the highest vapor pressure at a given temperature.A) SiS2B) RbClC) CH3SCH3D) BF3E) SbH3Answer: DDiff: 2 Page Ref: 11.5

43) Choose the substance with the lowest vapor pressure at a given temperature.A) CO2B) BeCl2C) BF3D) HeE) PF5Answer: BDiff: 2 Page Ref: 11.5


44) Place the following substances in order of increasing boiling point.

Ne Cl2 O2

A) Ne < Cl2 < O2B) Cl2 < O2 < NeC) O2 < Cl2 < NeD) Cl2 < Ne < O2E) Ne < O2 < Cl2Answer: EDiff: 2 Page Ref: 11.5

45) Place the following substances in order of increasing boiling point.

CH3CH2OH Ar CH3OCH3

A) Ar < CH3OCH3 < CH3CH2OHB) CH3CH2OH < Ar < CH3OCH3C) CH3CH2OH < CH3OCH3 < ArD) CH3OCH3 < Ar < CH3CH2OHE) Ar < CH3CH2OH < CH3OCH3 Answer: ADiff: 2 Page Ref: 11.5

46) Choose the substance with the highest boiling point.A) CH4B) KIC) CS2D) HFE) I2Answer: BDiff: 2 Page Ref: 11.5

47) Choose the substance with the lowest boiling point.A) H2SB) NBr3C) F2D) CF2H2E) H2O2Answer: CDiff: 2 Page Ref: 11.5


48) Which of the following substances would you predict to have the highest ΔHvap?A) CH3ClB) HClC) HOCH2CH2OHD) CH3CH2OHE) CH3CH2CH2CH3Answer: CDiff: 2 Page Ref: 11.5

49) Which of the following substances would you predict to have the highest ΔHvap?A) XeB) C6H6C) SiF4D) Br2E) N2Answer: DDiff: 2 Page Ref: 11.5

50) How much energy is required to vaporize 48.7 g of dichloromethane (CH2Cl2) at its boiling point, if its ΔHvap is 31.6 kJ/mol?A) 31.2 kJB) 6.49 kJC) 55.1 kJD) 15.4 kJE) 18.1 kJAnswer: EDiff: 3 Page Ref: 11.5

51) How much energy is required to vaporize 98.6 g of ethanol (C2H5OH) at its boiling point, if its ΔHvap is 40.5 kJ/mol?A) 86.7 kJB) 11.5 kJC) 18.9 kJD) 52.8 kJE) 39.9 kJAnswer: ADiff: 3 Page Ref: 11.5

52) How much energy is required to vaporize 158 g of butane (C4H10) at its boiling point, if its ΔHvap is 24.3 kJ/mol?A) 15.1 kJB) 66.1 kJC) 89.4 kJD) 11.2 kJE) 38.4 kJAnswer: B


Diff: 3 Page Ref: 11.5

53) Based on the figure above, the boiling point of diethyl ether under an external pressure of 1.32 atm is __________°C.A) 10B) 20C) 30D) 40E) 0Answer: DDiff: 3 Page Ref: 11.5

54) Based on the figure above, the boiling point of ethyl alcohol under an external pressure of 0.0724 atm is __________°C.A) 80B) 60C) 70D) 40E) 20Answer: EDiff: 3 Page Ref: 11.5

55) Based on the figure above, the boiling point of water under an external pressure of 0.316 atm is __________°C.A) 70B) 40C) 60D) 80E) 90Answer: A



56) Place the following substances in order of increasing vapor pressure at a given temperature.

SF6 SiH4 SF4

A) SF6 < SiH4 < SF4B) SiH4 < SF4 < SF6C) SF6 < SF4 < SiH4D) SF4 < SF6 < SiH4E) SiH4 < SF6 < SF4Answer: DDiff: 4 Page Ref: 11.5

57) Place the following substances in order of decreasing vapor pressure at a given temperature.

PF5 BrF3 CF4

A) BrF3 > PF5 > CF4B) BrF3 > CF4 > PF5C) PF5 > BrF3 > CF4D) CF4 > BrF3 > PF5E) CF4 > PF5 > BrF3Answer: EDiff: 4 Page Ref: 11.5

58) Place the following substances in order of increasing vapor pressure at a given temperature.

NF3 NH3 BCl3

A) NH3 < NF3 < BCl3B) NF3 < NH3 < BCl3C) BCl3 < NF3 < NH3D) NH3 < BCl3 < NF3E) BCl3 < NH3 < NF3Answer: ADiff: 4 Page Ref: 11.5


59) Place the following substances in order of decreasing vapor pressure at a given temperature.

BeF2 CH3OH OF2

A) CH3OH > OF2 > BeF2B) BeF2 > OF2 > CH3OHC) OF2 > CH3OH > BeF2D) OF2 > BeF2 > CH3OHE) BeF2 > CH3OH > OF2Answer: CDiff: 4 Page Ref: 11.5

60) Place the following substances in order of decreasing boiling point.

H2O N2 CO

A) CO > H2O > N2B) N2 > CO > H2OC) H2O > CO > N2D) CO > N2 > H2OE) N2 > H2O > COAnswer: CDiff: 4 Page Ref: 11.5


N2 O2 H2

A) O2 > H2 > N2B) N2 > H2 > O2C) N2 > O2 > H2D) O2 > N2 > H2E) H2 > N2 > O2Answer: DDiff: 4 Page Ref: 11.5



He Ar H2

A) He > H2 > ArB) H2 > He > ArC) He > Ar > H2D) Ar > He > H2E) H2 > Ar > HeAnswer: DDiff: 4 Page Ref: 11.5

63) Which of the following compounds has the highest boiling point?A) H2OB) H ClC) H2S D) N H3Answer: ADiff: 4 Page Ref: 11.5

64) Determine ΔHvap 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/molB) 79 kJ/molC) 24 kJ/molD) 13 kJ/molE) 34 kJ/molAnswer: CDiff: 5 Page Ref: 11.5

65) Determine the normal boiling point of a substance whose vapor pressure is 55.1 mm Hg at 35°C and has a ΔHvap of 32 .1 kJ/mol.A) 255 KB) 368 KC) 412 KD) 390. KE) 466 KAnswer: DDiff: 5 Page Ref: 11.5


66) Determine the vapor pressure (in mm Hg) of a substance at 29°C, whose normal boiling point is 76°C and has a ΔHvap of 38.7 kJ/mol. A) 80 mm HgB) 13 mm HgC) 21 mm HgD) 48 mm HgE) 96 mm HgAnswer: EDiff: 5 Page Ref: 11.5

67) Determine the vapor pressure (in torr) of a substance at 36°C, whose normal boiling point is 84°C and has a ΔHvap of 22.1 kJ/mol.A) 239 torrB) 31.8 torrC) 41.8 torrD) 147 torrE) 98 torrAnswer: ADiff: 5 Page Ref: 11.5

68) 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.Answer: CDiff: 1 Page Ref: 11.6

69) Define sublimation.A) the phase transition from solid to gasB) the phase transition from gas to solidC) the phase transition from gas to liquidD) the phase transition from liquid to gasE) the phase transition from liquid to solidAnswer: ADiff: 1 Page Ref: 11.6

70) Define freezing.A) the phase transition from solid to gasB) the phase transition from gas to solidC) the phase transition from gas to liquidD) the phase transition from liquid to gasE) the phase transition from liquid to solidAnswer: EDiff: 1 Page Ref: 11.6


71) At atmospheric pressure, dry ice __________.A) freezesB) depositsC) sublimesD) meltsE) boilsAnswer: CDiff: 1 Page Ref: 11.6

72) The melting point of water is __________.A) 0°CB) 32°CC) 212°CD) 100°CE) 273°CAnswer: ADiff: 1 Page Ref: 11.6

73) The freezing point of water is __________.A) 0°CB) 32°CC) 212°CD) 100°CE) 273°CAnswer: ADiff: 1 Page Ref: 11.6

74) The boiling point of water is __________.A) 0°CB) 32°CC) 212°CD) 100°CE) 273°CAnswer: DDiff: 1 Page Ref: 11.6

75) The heat of vaporization of water at 100°C is 40.66 kJ/mol. Calculate the quantity of heat that is absorbed/released when 9.00 g of steam condenses to liquid water at 100°C. A) 20.3 kJ of heat are absorbed.B) 20.3 kJ of heat are released.C) 81.3 kJ of heat are absorbed.D) 81.3 kJ of heat are released.Answer: BDiff: 4 Page Ref: 11.7


76) Calculate the total quantity of heat required to convert 25.0 g of liquid CCl4(l) from 35.0°C to gaseous CCl4 at 76.8°C (the normal boiling point for CCl4). The specific heat of CCl4(l) is 0.857 J/(g · °C), its heat of fusion is 3.27 kJ/mol, and its heat of vaporization is 29.82 kJ/mol. A) 0.896 kJB) 1.43 kJC) 5.74 kJD) 6.28 kJAnswer: CDiff: 4 Page Ref: 11.7

77) The enthalpy change for converting 1.00 mol of ice at -50.0°C to water at 70.0°C is __________ kJ. The specific heats of ice, water, and steam are 2.09 J/gK, 4.18 J/gK, and 1.84 J/gK, respectively. For H2O, ΔHfus = 6.01 kJ/mol, and ΔHvap = 40.67 kJ/mol.

A) 12.28B) 6.41C) 13.16D) 7154E) 9.40Answer: CDiff: 4 Page Ref: 11.7

78) The enthalpy change for converting 10.0 g of ice at -25.0°C to water at 80.0°C is __________ kJ. The specific heats of ice, water, and steam are 2.09 J/gK, 4.18 J/gK, and 1.84 J/gK, respectively. For H2O, ΔHfus = 6.01 kJ/mol, and ΔHvap = 40.67 kJ/mol.

A) 12.28B) 6.16C) 3870D) 7.21E) 9.88Answer: DDiff: 4 Page Ref: 11.7

79) The fluorocarbon C2Cl3F3 has a normal boiling point of 47.6°C. The specific heats of

C2Cl3F3(l) and C2Cl3F3 (g) are 0.91 J/gK and 0.67 J/gK, respectively. The heat of vaporization

of the compound is 27.49 kJ/mol. The heat required to convert 50.0 g of the compound from the liquid at 5.0°C to the gas at 80.0°C is __________ kJ.A) 8.19B) 1454C) 30.51D) 3031E) 10.36Answer: EDiff: 4 Page Ref: 11.7


80) Ethanol (C2H5OH) melts at -114°C. The enthalpy of fusion is 5.02 kJ/mol. The specific

heats of solid and liquid ethanol are 0.97 J/gK and 2.3 J/gK, respectively. How much heat (kJ) is needed to convert 25.0 g of solid ethanol at -135°C to liquid ethanol at -50°C?A) 207.3 kJB) -12.7 kJC) 6.91 kJD) 4192 kJE) 9.21 kJAnswer: CDiff: 4 Page Ref: 11.7

81) Ethyl chloride, C2H5Cl, is used as a local anesthetic. It works by cooling tissue as it vaporizes; its heat of vaporization is 26.4 kJ/mol. How much heat could be removed by 20.0 g of ethyl chloride?A) 8.18 kJB) 341 kJC) 528 kJ D) 3410 kJAnswer: ADiff: 4 Page Ref: 11.7

82) How much heat is released when 105 g of steam at 100.0°C is cooled to ice at -15.0°C? The enthalpy of vaporization of water is 40.67 kJ/mol, the enthalpy of fusion for water is 6.01 kJ/mol, the molar heat capacity of liquid water is 75.4 J/(mol · °C), and the molar heat capacity of ice is 36.4 J/(mol · °C). A) 54.8 kJB) 273 kJC) 319 kJD) 347 kJAnswer: CDiff: 4 Page Ref: 11.7


83) 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.

ΔHvap = 40.7 kJ/mol

Cliq = 4.18 J/g∘C

Cgas = 2.01 J/g∘C

Csol = 2.09 J/g∘C

Tmelting = 0∘C

Tboiling = 100∘C

A) 63.5 kJB) 87.7 kJC) 10.9 kJD) 52.7 kJE) 91.7 kJAnswer: BDiff: 5 Page Ref: 11.7

84) 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.

ΔHvap = 33.9 kJ/molΔHfus = 9.8 kJ/molCliq = 1.73 J/g°CCgas = 1.06 J/g°CCsol = 1.51 J/g°CTmelting = 279.0 KTboiling = 353.0 K

A) 38.9 kJB) 95.4 kJC) 67.7 kJD) 54.3 kJE) 74.4 kJAnswer: CDiff: 5 Page Ref: 11.7


85) 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.

ΔHfus = 7.27 kJ/molCliq = 2.16 J/g°CCgas = 1.29 J/g°CCsol = 1.65 J/g°CTmelting = -95.0°C

A) 8.48 kJB) 18.5 kJC) 32.2 kJD) 29.4 kJE) 9.97 kJAnswer: DDiff: 5 Page Ref: 11.7

86) 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.

ΔHvap = 33.9 kJ/molΔHfus = 9.8 kJ/molCliq = 1.73 J/g°CCgas = 1.06 J/g°CCsol = 1.51 J/g°CTmelting = 279.0 KTboiling = 353.0 K

A) 17.6 kJB) 11.8 kJC) 70.2 kJD) 10.5 kJE) 29.4 kJAnswer: EDiff: 5 Page Ref: 11.7

87) 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 co-exist.Answer: CDiff: 1 Page Ref: 11.8


88) Assign the appropriate labels to the phase diagram shown below.

A) A = liquid, B = solid, C = gas, D = critical pointB) A = gas, B = solid, C = liquid, D = triple pointC) A = gas, B = liquid, C = solid, D = critical pointD) A = solid, B = gas, C = liquid, D = supercritical fluidE) A = liquid, B = gas, C = solid, D = triple pointAnswer: BDiff: 1 Page Ref: 11.8

89) 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 atm 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 ΔHvap.E) None of the above are true.Answer: C



90) 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 vaporizationB) sublimation, followed by depositionC) vaporization, followed by depositionD) fusion, followed by vaporizationE) No phase change will occur under the conditions specified.Answer: DDiff: 1 Page Ref: 11.8

91) 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.Answer: EDiff: 1 Page Ref: 11.9

92) Identify the compound with the highest boiling point.A) CH4B) NH3C) HFD) H2SE) H2OAnswer: EDiff: 1 Page Ref: 11.9


93) Give the coordination number for a body-centered cubic cell.A) 4B) 6C) 8D) 10E) 12Answer: CDiff: 1 Page Ref: 11.9

94) Determine the radius of an Al atom (in pm) if the density of aluminum is 2.71 g/cm3. Aluminum crystallizes in a face centered cubic structure with an edge length of 2 2 r.A) 143 pmB) 227 pmC) 96 pmD) 172 pmE) 193 pmAnswer: ADiff: 5 Page Ref: 11.11

95) A metal crystallizes in a face centered cubic structure and has a density of 11.9 g/cm3. If the radius of the metal atom is 138 pm, what is the identity of the metal?A) AtB) PdC) MnD) FeE) CrAnswer: BDiff: 5 Page Ref: 11.11

96) Vanadium crystallizes in a body centered cubic structure and has an atomic radius of 131 pm. Determine the density of vanadium, if the edge length of a bcc structure is 4r/ 3 .A) 3.06 g/cm3

B) 12.2 g/cm3

C) 6.11 g/cm3

D) 2.77 g/cm3

E) 8.46 g/cm3Answer: CDiff: 5 Page Ref: 11.11

97) Which of the following is considered a molecular solid?A) CuB) NH4NO3C) I2D) XeE) None of these is a molecular solid.Answer: CDiff: 1 Page Ref: 11.12


98) Which of the following is considered an ionic solid?A) (NH4)2CO3B) CCl4C) SeBr2D) XeF4E) None of these is an ionic solid.Answer: ADiff: 1 Page Ref: 11.12

99) Which of the following is considered an atomic solid?A) Br2B) CsClC) N2D) NbE) None of these is an atomic solid.Answer: DDiff: 1 Page Ref: 11.12

100) Which of the following is considered a nonbonding atomic solid?A) NeB) FeC) I2D) CaE) LiAnswer: ADiff: 1 Page Ref: 11.12

101) Identify the type of solid for AgCl.A) metallic atomic solidB) ionic solidC) nonbonding atomic solidD) molecular solidE) networking atomic solidAnswer: BDiff: 1 Page Ref: 11.12

102) Identify the type of solid for ice.A) metallic atomic solidB) ionic solidC) nonbonding atomic solidD) molecular solidE) networking atomic solidAnswer: DDiff: 1 Page Ref: 11.12


103) Identify the type of solid for gold.A) metallic atomic solidB) ionic solidC) nonbonding atomic solidD) molecular solidE) networking atomic solidAnswer: ADiff: 1 Page Ref: 11.12

104) Identify the type of solid for diamond.A) metallic atomic solidB) ionic solidC) nonbonding atomic solidD) molecular solidE) networking atomic solidAnswer: EDiff: 1 Page Ref: 11.12

105) Identify the type of solid for argon.A) metallic atomic solidB) ionic solidC) nonbonding atomic solidD) molecular solidE) networking atomic solidAnswer: CDiff: 1 Page Ref: 11.12

106) Which of the following substances should have the highest melting point?A) CO2B) SrSC) XeD) F2E) MgOAnswer: EDiff: 1 Page Ref: 11.12

107) Which of the following substances should have the highest melting point?A) FeB) NeC) XeD) N2E) COAnswer: ADiff: 1 Page Ref: 11.12


Algorithmic Questions

1) What is the edge length of a face-centered cubic unit cell made up of atoms having a radius of 128 pm?A) 181 pmB) 362 pmC) 512 pmD) 1020 pmAnswer: BDiff: 5 Page Ref: 11.11

2) Nickel has a face-centered cubic structure and has a density of 8.90 g/cm3. What is its atomic radius? A) 125 pmB) 249 pmC) 353 pmD) 997 pmAnswer: ADiff: 5 Page Ref: 11.11

3) Gold crystallizes in a face-centered cubic structure. What is the edge length of the unit cell if the atomic radius of gold is 144 pm? A) 204 pmB) 288 pmC) 333 pmD) 407 pmAnswer: DDiff: 5 Page Ref: 11.11

4) Cesium has a radius of 272 pm and crystallizes in a body-centered cubic structure. What is the edge length of the unit cell?A) 314 pmB) 385 pmC) 544 pmD) 628 pmAnswer: DDiff: 5 Page Ref: 11.11

5) Lithium crystallizes in a body-centered cubic structure. What is the coordination number of each atom?A) 4B) 6C) 8D) 12Answer: CDiff: 5 Page Ref: 11.11


6) Na Cl crystallizes in a cubic unit cell with Cl- ions on each corner and each face. How many Na+ and Cl- ions are in each unit cell of Na Cl?A) 1 Na+ ion and 1 Cl- ionB) 2 Na+ ions and 2 Cl- ionsC) 4 Na+ ions and 4 Cl- ionsD) 8 Na+ ions and 8 Cl- ionsAnswer: CDiff: 5 Page Ref: 11.11

7) How many H- ions are around each Na+ ion in NaH, which has a cubic unit cell with H- ions on each corner and each face?A) 1B) 4C) 6D) 8Answer: CDiff: 5 Page Ref: 11.11

8) Which of the following forms a molecular solid?A) NH4NO3B) C6H4Cl2C) SiO2 D) copperAnswer: BDiff: 1 Page Ref: 11.12

9) Which of the following forms an ionic solid?A) AgB) C7H15NH2C) Rb I D) S O3Answer: CDiff: 1 Page Ref: 11.12

10) Which type of bonding does Sr form upon solidification? A) covalent networkB) ionicC) metallicD) molecularAnswer: CDiff: 2 Page Ref: 11.12


Matching Questions

Match the following.

A) H2 + H2OB) dispersion forcesC) hydrogen bondingD) ion-dipole forcesE) ionic bondF) dipole-dipole forces

1) LiIDiff: 1 Page Ref: 11.3

2) CH3OHDiff: 1 Page Ref: 11.3

3) CH3CH3Diff: 1 Page Ref: 11.3

4) CH2F2Diff: 1 Page Ref: 11.3

5) LiI + H2ODiff: 1 Page Ref: 11.3

Answers: 1) E 2) C 3) B 4) F 5) D

Short Answer Questions

1) Why do O, F and N, when bonded to H, form such strong intermolecular attractions to neighboring molecules? Make sure to be specific.Answer: Oxygen, fluorine and nitrogen are all very small and highly electronegative elements. When they bond to hydrogen they form extremely polar bonds. These extremely polar bonds formed between small atoms can get very close to interact with other molecules. The closer the molecules get, the more strongly they can interact. In addition, these three elements usually have lone pair electrons which make the attractions to other molecules even stronger. Diff: 1 Page Ref: 11.3

2) Define viscosity.Answer: Viscosity is the resistance of a liquid to flow.Diff: 2 Page Ref: 11.4


3) Why does the temperature of a substance stay constant during a phase change such as vaporization?Answer: The energy added to the substance is not used to raise the kinetic energy of the substance. Instead it is "used up" in breaking the intermolecular attractions between particles to take them from a liquid (with intermolecular attractions) to a gas (with no intermolecular attractions).Diff: 1 Page Ref: 11.5

4) Define volatile.Answer: Liquids that vaporize easily.Diff: 1 Page Ref: 11.5

5) Define boiling point of a liquid.Answer: The temperature at which the vapor pressure equals the external pressure.Diff: 1 Page Ref: 11.5

6) Define dynamic equilibrium.Answer: Dynamic equilibrium is when the rate of condensation equals the rate of vaporization.Diff: 2 Page Ref: 11.5

7) Why is the ΔHvap higher than ΔHfus for a given compound?Answer: Vaporizing a substance requires the complete "breaking" of all intermolecular attractions, whereas the melting of a substance only requires the breaking of a portion of the intermolecular attractions. Diff: 1 Page Ref: 11.6

8) Sketch the phase diagram of benzene. Make sure to label the axes and the different phases of benzene. Use the physical data provided below.

melting point = 279 Kboiling point = 353 KTc = 562 KPc = 48.4 atmTriple Point = 0.05 atm, 279 K

Answer: Sketch should include all given information showing fusion and vaporization curves.Diff: 3 Page Ref: 11.8

9) Give the edge length in terms of r for a simple cubic cell.Answer: 2rDiff: 1 Page Ref: 11.9

10) Describe the difference between the conduction band and the valence band.Answer: The valence band is the group of highest energy occupied orbitals in the solid. The conduction band is the set of empty orbitals that are higher in energy than the valence band. In metals the difference in energy between the valence band and conduction band is fairly small, making it easy for electrons to move from the valence band to the conduction band.Diff: 2 Page Ref: 11.12


chemistry: a molecular approach, 2e...

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