Full Test Bank The Liquid And Solid States Chapter 10 - Introduction to Chemistry 5e Answer Key + Test Bank by Rich Bauer. DOCX document preview.
Introduction to Chemistry, 5e (Bauer)
Chapter 10 The Liquid and Solid States
1) Three phases of water are shown in the figure. List the terms used to identify the phase changes indicated by the arrows.
A) A = sublimation, B = vaporization, C = freezing
B) A = condensation, B = sublimation, C = melting
C) A = freezing, B = vaporization, C = melting
D) A = deposition, B = vaporization, C = melting
E) A = deposition, B = sublimation, C = freezing
2) Three phases of water are shown in the figure. List the terms used to identify the phase changes indicated by the arrows.
A) A = sublimation, B = vaporization, C = freezing
B) A = vaporization, B = condensation, C = melting
C) A = vaporization, B = deposition, C = melting
D) A = sublimation, B = condensation, C = freezing
E) A = condensation, B = sublimation, C = freezing
3) Which of the following statements is correct?
A) A liquid which has a high boiling point has a higher vapor pressure at a given temperature than a liquid with a low boiling point.
B) Liquids boil at higher temperatures in the mountains due to the higher altitude.
C) Evaporation is an exothermic process, since heat is given off when a substance vaporizes.
D) Since acetone (nail polish remover) evaporates more readily than water, one would assume that acetone has weaker intermolecular forces.
E) The phase change from solid to gas is exothermic.
4) Which of the following statements is correct?
A) The phase change from solid to liquid is exothermic.
B) Liquids boil at lower than normal temperatures in Death Valley, since it is below sea level.
C) A substance with a low boiling point would be expected to have a relatively low vapor pressure at a low temperature.
D) The phase change from liquid to gas is exothermic.
E) When a substance condenses, heat energy is given off.
5) Which of the following statements is correct?
A) When the temperature of a sample of liquid is increased, the molecules move faster, but there is no change in the vapor pressure of the sample.
B) The melting point of metallic sodium is 97.8ºC, so at a temperature of 25ºC, it is a liquid.
C) If you cook an egg on a mountain, it will require a short cooking time, due to the high elevation.
D) When liquids evaporate, it requires an input of energy from the surroundings, so the surroundings become warm.
E) Nitrogen gas has a boiling point of −196ºC, so if it is cooled to −200ºC, it condenses.
6) Which of the molecular-level images in the figure shows the liquid and vapor phases in equilibrium in a closed container?
A) I, II, and III
B) none of the images
C) I
D) V
E) V and VI
7) From the vapor pressure curve of acetone, it can be seen that the normal boiling point of acetone is about ________.
A) –50ºC
B) 0ºC
C) 50ºC
D) 55ºC
E) 100ºC
8) From the vapor pressure curve of propane, it can be seen that the normal boiling point of propane is about ________.
A) −137ºC
B) −120ºC
C) −60ºC
D) −42ºC
E) 0ºC
9) The atmospheric pressure on Mount Everest is about 0.30 atm. From the vapor pressure curve of propane, it can be seen the boiling point of propane at this elevation is about ________.
A) −137ºC
B) −120ºC
C) −67ºC
D) −42ºC
E) 0ºC
10) Which of the following statements is correct?
A) At the melting point of a substance, the solid, liquid, and gas phases are all in equilibrium.
B) The freezing point and the melting point of a substance are the same.
C) There is no fundamental difference in the melting process for covalent substances and ionic substances.
D) In order for a substance to go from the gas phase to the liquid phase, it must absorb energy from the surroundings.
E) In order for a substance to go from the liquid phase to the gas phase, it must give off energy to the surroundings.
11) What phase transition is occurring between points B and C on the heating curve?
A) melting
B) condensation
C) evaporation
D) sublimation
E) deposition
12) What phase transition is occurring between points D and E on the heating curve?
A) melting
B) freezing
C) evaporation
D) sublimation
E) deposition
13) What phase change is occurring in the figure, and is it endothermic or exothermic?
A) melting; exothermic
B) freezing; endothermic
C) freezing; exothermic
D) melting; endothermic
E) condensation; endothermic
14) What phase change is occurring in the figure, and is it endothermic or exothermic?
A) melting; exothermic
B) freezing; endothermic
C) freezing; exothermic
D) melting; endothermic
E) sublimation; endothermic
15) What phase transition is occurring between points B and C on the cooling curve?
A) melting
B) condensation
C) evaporation
D) sublimation
E) deposition
16) What phase transition is occurring between points D and E on the cooling curve?
A) melting
B) freezing
C) evaporation
D) sublimation
E) deposition
17) The pictured change of state occurs at constant temperature even though heat is being removed. Where does this change of state occur on the cooling curve?
A) AB
B) BC
C) CD
D) DE
E) EF
18) The pictured change of state occurs at constant temperature even though heat is being removed. Where does this change of state occur on the cooling curve?
A) AB
B) BC
C) CD
D) DE
E) EF
19) The pictured change of state occurs at constant temperature even though heat is being added. Where does this change of state occur on the cooling curve?
A) AB
B) BC
C) CD
D) DE
E) EF
20) The pictured change of state occurs at constant temperature even though heat is being added. Where does this change of state occur on the cooling curve?
A) AB
B) BC
C) CD
D) DE
E) EF
21) The diagram represents the physical state of a substance. Where does this physical state occur on the heating curve?
A) AB
B) BC
C) CD
D) DE
E) EF
22) The diagram represents the physical state of a substance. Where does this physical state occur on the heating curve?
A) AB
B) BC
C) CD
D) DE
E) EF
23) The diagram represents the physical state of a substance. Where does this physical state occur on the cooling curve?
A) AB
B) BC
C) CD
D) DE
E) EF
24) The diagram represents the physical state of a substance. Where does this physical state occur on the cooling curve?
A) AB
B) BC
C) CD
D) DC
E) EF
25) Calculate the amount of heat energy required to evaporate 55.0 g of water at 100.0ºC. (molar heat of vaporization of liquid water = 4.07 × 104 J/mol)
A) 1.24 × 102 kJ
B) 2.24 × 103 kJ
C) 4.03 × 104 kJ
D) 1.24 × 108 kJ
E) 2.43 × 10−2 kJ
26) Calculate the amount of heat energy required to evaporate 27.5 g of water at 100.0ºC. (molar heat of vaporization of liquid water = 4.07 × 104 J/mol)
A) 62.1 kJ
B) 1.12 × 103 kJ
C) 2.02 × 104 kJ
D) 6.20 × 107 kJ
E) 1.22 × 10−2 kJ
27) Calculate the amount of heat energy, in units of kilojoules, required to evaporate 35.0 g of ethanol, CH3CH2OH, at 78.4ºC, ethanol's boiling point. (The molar heat of vaporization of liquid ethanol is 3.86 × 104 J/mol. The molar mass of ethanol is 46.07 g/mol.)
A) 29.3 kJ
B) 1.35 × 103 kJ
C) 1.10 × 103 kJ
D) 8.38 × 102 kJ
E) 9.21 × 10−4 kJ
28) Calculate the amount of heat energy required to melt 25.0 g of ice at 0.0°C. (molar heat of fusion of ice = 6.01 × 103 J/mol)
A) 1.50 × 102 kJ
B) 8.34 kJ
C) 4.33 kJ
D) 7.50 × 102 kJ
E) 1.50 × 10−1 kJ
29) Calculate the amount of heat energy, in units of kilojoules, required to melt 75.0 g of ice at 0.0ºC. (molar heat of fusion of ice = 6.01 × 103 J/mol)
A) 4.50 × 102 kJ
B) 25.0 kJ
C) 13.0 kJ
D) 2.25 × 103 kJ
E) 4.50 × 10−1 kJ
30) Calculate the amount of heat energy required to convert 55.0 g of water at 62.5ºC to steam at 124.0°C. (Cwater = 4.184 J/g°C; Csteam = 2.02 J/g°C; molar heat of vaporization of liquid water = 4.07 × 104 J/mol)
A) 2.25 × 103 kJ
B) 1.23 × 102 kJ
C) 0.862 kJ
D) 1.36 × 102 kJ
E) 2.67 kJ
31) Calculate the amount of heat energy required to convert 27.5 g of water at 62.5°C to steam at 124.0°C. (Cwater = 4.184 J/g°C; Cice = 2.03 J/gºC; Csteam = 2.02 J/g°C; molar heat of fusion of ice = 6.01 × 103 J/mol; molar heat of vaporization of liquid water = 4.07 × 104 J/mol)
A) 6.15 × 104 kJ
B) 1.23 × 102 kJ
C) 4.31 × 102 kJ
D) 67.8 kJ
E) 1.33 kJ
32) Calculate the amount of heat energy, in units of kilojoules, required to convert 50.0 g of liquid ethanol, CH3CH2OH, at 25.5°C to gaseous ethanol at 92.0°C. (Cethanol liquid = 2.44 J/g°C; Cethanol gas = 1.42 J/g°C; molar heat of vaporization of liquid ethanol = 3.86 × 104 J/mol. The boiling point of ethanol is 78.4°C and its molar mass is 46.07 g/mol.)
A) 49.2 kJ
B) 1.93 × 103 kJ
C) 0.862 kJ
D) 1.35 × 102 kJ
E) 2.67 kJ
33) Calculate the amount of heat energy required to convert 35.0 g of ice at –12.5°C to water at 24.0°C. (Cwater = 4.184 J/g°C; Cice = 2.03 J/g°C; molar heat of fusion of ice = 6.01 × 103 J/mol)
A) 8.88 × 102 J
B) 1.17 × 104 J
C) 1.61 × 1010 J
D) 3.51 × 103 J
E) 1.61 × 104 J
34) Which of the following is not an attractive force that acts between the individual molecules of CH3OH?
A) London dispersion forces
B) dipole-dipole forces
C) hydrogen-bonding forces
D) covalent bonds
E) none of these is correct
35) Which of the following statements regarding intermolecular forces is incorrect?
A) An intermolecular force is an attractive force that operates between molecules.
B) Bonding forces are much stronger than intermolecular forces.
C) London dispersion forces occur in all atoms and molecules.
D) London dispersion forces are the result of permanent dipoles in atoms or molecules.
E) Molecules which have hydrogen bonded to F, O, or N can undergo hydrogen-bonding.
36) The physical properties of a substance influenced by the strength of intermolecular forces include all of the following except
A) melting point.
B) boiling point.
C) viscosity.
D) vapor pressure.
E) mass.
37) The physical properties of a substance influenced by the strength of intermolecular forces include all of the following except
A) density.
B) boiling point.
C) surface tension.
D) melting point.
E) mass.
38) Which of the following substances is most likely to be a gas at room temperature and atmospheric pressure?
A) I2
B) Pb
C) Ar
D) CCl4
E) C8H18
39) Which of the following substances is most likely to be a gas at room temperature and atmospheric pressure?
A) Ni
B) Hg
C) CO2
D) C7H16
E) CBr4
40) Which of the following substances is most likely to be a gas at room temperature and atmospheric pressure?
A) Cs
B) SO2
C) I2
D) CCl4
E) Ni
41) Which of the following substances is most likely to be a gas at room temperature?
A) CBr4
B) F2
C) Mn
D) C6H14
E) Sr
42) Rank the following substances in order of increasing boiling point: Cl2, Ar, Ne, Br2
A) Cl2 < Ar < Ne < Br2
B) Ar < Ne < Br2 < Cl2
C) Ne < Ar < Br2 < Cl2
D) Ne < Ar < Cl2 < Br2
E) Cl2 < Br2 < Ar < Ne
43) Rank the following substances in order of increasing boiling point: F2, Ne, He, Cl2
A) F2 < Ne < He < Cl2
B) F2 < He < Ne < Cl2
C) F2 < Cl2 < He < Ne
D) He < Ne < F2 < Cl2
E) Cl2 < F2 < Ne < He
44) Rank the following substances in order of increasing boiling point: O2, Ne, Ar, H2
A) O2 < Ne < Ar < H2
B) O2 < Ar < Ne < H2
C) H2 < Ne < Ar < O2
D) H2 < Ne < O2 < Ar
E) Ar < O2 < Ne < H2
45) Which of the following molecules experience dipole-dipole forces?
A) CO2
B) SO2
C) CCl4
D) H2S
E) both SO2 and H2S
46) Which of the following molecules experience dipole-dipole forces?
A) NO2
B) CO2
C) CBr4
D) SO3
E) F2
47) Which of the following molecules experience dipole-dipole forces?
A) NO
B) Cl2
C) CH4
D) SiH4
E) all of these
48) Which of the molecules in the figure has hydrogen bonding in the pure liquid state?
A) I only
B) II only
C) III only
D) II and III
E) I and II
49) Which of the molecules in the figure has hydrogen bonding in the pure liquid state?
A) I only
B) II only
C) III only
D) II and III
E) I and II
50) Which of the following substances can participate in hydrogen bonding?
A) CH4
B) CHCl3
C) H2S
D) NH3
E) both H2S and NH3
51) Which of the following substances can participate in hydrogen bonding?
A) SiH4
B) CH2Cl2
C) H2O
D) PH3
E) both H2O and PH3
52) Which of the following substances can participate in hydrogen bonding?
A) CH4
B) HF
C) CH3COCH3
D) SiH4
E) all of these choices are correct
53) Rank the following substances in order of increasing intermolecular forces: He, HF, F2, Ne
A) He < HF < F2 < Ne
B) He < HF < Ne < F2
C) He < Ne < F2 < HF
D) He < F2 < Ne < HF
E) HF < Ne < F2 < He
54) Rank the following substances in order of increasing intermolecular forces: Ne, NH3, H2, O2
A) Ne < NH3 < H2 < O2
B) Ne < NH3 < O2 < H2
C) NH3 < O2 < H2 < Ne
D) O2 < H2 < Ne < NH3
E) H2 < Ne < O2 < NH3
55) Rank the following substances in order of increasing intermolecular forces: Ar, H2O, N2, O2
A) Ar < H2O < N2 < O2
B) Ar < H2O < O2 < N2
C) H2O < N2 < O2 < Ar
D) N2 < O2 < Ar < H2O
E) Ar < N2 < O2 < H2O
56) Which of the following has the strongest London dispersion forces?
A) CH4
B) CF4
C) CCl4
D) CBr4
E) CI4
57) Which of the following has the highest vapor pressure at a given temperature?
A) CH4
B) CF4
C) CCl4
D) CBr4
E) CI4
58) Which of the following has the highest boiling point?
A) CH4
B) CF4
C) CCl4
D) CBr4
E) CI4
59) Which of the following has the highest boiling point?
A) H2
B) H2O
C) H2S
D) H2Se
E) H2Te
60) Which of the following has the highest boiling point?
A) H2
B) HF
C) HCl
D) HBr
E) HI
61) Which of the following statements regarding intermolecular forces is incorrect?
A) Hydrogen bonding is the strongest of the intermolecular forces.
B) London dispersion forces increase with increasing molecular size.
C) Dipole-dipole forces are present in all atoms and molecules.
D) In order for a pure substance to participate in hydrogen bonding, it must have hydrogen bonded to F, O, or N.
E) Intermolecular forces are much weaker than bonding forces.
62) Which of the following statements regarding intermolecular forces is incorrect?
A) Hydrogen bonding is the strongest of the intermolecular forces for substances of similar molar mass.
B) London dispersion forces are present in all atoms and molecules.
C) Dipole-dipole forces increase with increasing molecular size.
D) Bonding forces are much stronger than intermolecular forces.
E) Hydrogen bonding is the reason for the abnormally high boiling point of water.
63) Which choice correctly lists the intermolecular forces present in CH3NH2?
A) London forces only
B) dipole-dipole forces only
C) London forces, dipole-dipole forces, and hydrogen bonding
D) dipole-dipole forces and hydrogen bonding
E) hydrogen bonding only
64) Which choice correctly lists the intermolecular forces present in CH4?
A) London forces only
B) London forces and dipole-dipole forces
C) London forces, dipole-dipole forces, and hydrogen bonding
D) dipole-dipole forces and hydrogen bonding
E) London forces and hydrogen bonding
65) Which choice correctly lists the intermolecular forces present in CH3Br?
A) London forces only
B) London forces and dipole-dipole forces
C) London forces, dipole-dipole forces, and hydrogen bonding
D) dipole-dipole forces and hydrogen bonding
E) London forces and hydrogen bonding
66) Arrange the following substances in order of increasing boiling point:
CH3OH, CH4, CH3CH2OH, HOCH2CH2OH
A) CH3OH < CH4 < CH3CH2OH < HOCH2CH2OH
B) CH4 < CH3OH < CH3CH2OH < HOCH2CH2OH
C) CH4 < CH3OH < HOCH2CH2OH < CH3CH2OH
D) CH3OH < CH4 < HOCH2CH2OH < CH3CH2OH
E) HOCH2CH2OH < CH3CH2OH < CH3OH < CH4
67) Arrange the following substances in order of increasing boiling point:
N2, H2, NH3, PH3
A) H2 < N2 < PH3 < NH3
B) N2 < H2 < PH3 < NH3
C) H2 < N2 < NH3 < PH3
D) N2 < PH3 < NH3 < H2
E) NH3 < PH3 < N2 < H2
68) Select the pair of substances which has the one with the higher equilibrium vapor pressure at a given temperature listed first.
A) H2O, H2S
B) CH3CH2OH, CH3OH
C) CH3COCH3, CH3CH2CH2OH
D) NH3, PH3
E) Br2, Cl2
69) Select the pair of substances which has the one with the higher equilibrium vapor pressure at a given temperature listed first.
A) H2O, HCl
B) CH3OH, CH4
C) CH3CH2CH2OH, CH3COCH3
D) AsH3, PH3
E) Cl2, Br2
70) Which of the following statements regarding the liquid state is incorrect?
A) Liquids are about 1000 times denser than gases.
B) Liquids are normally about 90-95% as dense as their corresponding solid.
C) The viscosity of a liquid is a measure of its resistance to flow.
D) Molecules with high intermolecular forces will have high surface tension.
E) Surface tension increases as temperature increases.
71) Which of the following statements regarding the liquid state is incorrect?
A) Liquid water is denser than ice (solid water).
B) The viscosity of a liquid is related to its intermolecular forces—the stronger the forces, the higher the viscosity.
C) As temperature increases, so will the viscosity of a liquid.
D) Substances with strong intermolecular forces have high surface tension.
E) Detergents interfere with the attractive forces among water molecules to lower the surface tension of the water.
72) Which of the following statements regarding the liquid state is incorrect?
A) Detergents increase the surface tension of water, in order to help it stay in droplet form.
B) If ice were denser than liquid water, lakes would freeze from the bottom up.
C) In the summer, one would use a motor oil with a high viscosity rating to better lubricate the engine at high temperatures.
D) A liquid such as C15H32 would be expected to be more viscous than C6H14.
E) Water rises in a glass capillary tube due to the interactions between the water molecules and the glass.
73) Which of the following statements regarding the solid state is incorrect?
A) Solids are not very compressible.
B) Solids have rigid shapes and definite sizes.
C) If a material solidifies in a partially disordered state, it is an amorphous solid.
D) Substances which solidify in a very orderly manner form crystalline solids.
E) Glass is an example of a crystalline solid.
74) Which of the following statements regarding the solid state is incorrect?
A) Most polymers, such as rubbers and plastics, are amorphous.
B) Minerals, such as quartz and amethyst, are crystalline solids.
C) Solids normally do not flow.
D) The particles of a solid are held in a rigid, 3-dimensional array.
E) The arrangement of the particles in a crystal lattice is called space packing.
75) Which of the following is not one of the classifications into which solids can be organized?
A) metallic
B) ionic
C) molecular
D) liquid crystals
E) network
76) Which of the following statements regarding the solid state is incorrect?
A) Many metals follow a close-packing arrangement of their atoms, much like the way fruit is stacked in the grocery store.
B) The forces holding the particles together in a solid will affect their properties.
C) Network solids tend to have very high melting points.
D) Nonpolar molecular solids tend to be good conductors of heat and electricity.
E) Ionic solids tend to be brittle.
77) A solid substance has a very high melting point, is very hard, and is a nonconductor whether molten or solid. This substance is probably a(n) ________ solid.
A) metallic
B) ionic
C) network
D) nonpolar molecular
E) polar molecular
78) A solid substance has a moderate melting point, is fairly soft, and is a nonconductor. This substance is probably a(n) ________ solid.
A) metallic
B) ionic
C) network
D) nonpolar molecular
E) polar molecular
79) A solid substance has a high melting point, is hard, and is a good conductor of both heat and electricity. It is also malleable and ductile. This substance is probably a(n) ________ solid.
A) metallic
B) ionic
C) network
D) nonpolar molecular
E) polar molecular
80) A solid substance has a high melting point, is hard, brittle, and conducts electricity when molten. This substance is probably a(n) ________ solid.
A) metallic
B) ionic
C) network
D) nonpolar molecular
E) polar molecular
81) A solid substance has a very low melting point, is soft, and does not conduct heat or electricity. This substance is probably a(n) ________ solid.
A) metallic
B) ionic
C) network
D) nonpolar molecular
E) polar molecular
82) The forces that hold graphite, C(s), together in the solid state are
A) ionic bonds.
B) dipole-dipole forces.
C) London dispersion forces only.
D) covalent bonds and London dispersion forces.
E) attractions between nuclei and delocalized valence electrons.
83) The forces that hold Cu together in the solid state are
A) ionic bonds.
B) dipole-dipole forces.
C) London dispersion forces only.
D) covalent bonds.
E) attractions between nuclei and delocalized valence electrons.
84) The forces that hold CO2 together in the solid state are
A) ionic bonds.
B) dipole-dipole forces.
C) London dispersion forces only.
D) covalent bonds.
E) attractions between nuclei and delocalized valence electrons.
85) The forces that hold NH3 together in the solid state are
A) ionic bonds.
B) dipole-dipole forces and hydrogen bonding.
C) London dispersion forces only.
D) covalent bonds.
E) attractions between nuclei and delocalized valence electrons.
86) The forces that hold CaF2 together in the solid state are
A) ionic bonds.
B) dipole-dipole forces.
C) London dispersion forces only.
D) covalent bonds.
E) attractions between nuclei and delocalized valence electrons.
87) Identify the type of solid shown in the image.
A) metallic
B) ionic
C) network
D) nonpolar molecular
E) polar molecular
88) Identify the type of solid shown in the image.
A) metallic
B) ionic
C) network
D) nonpolar molecular
E) polar molecular
89) Identify the type of solid shown in the image.
A) metallic
B) ionic
C) network
D) nonpolar molecular
E) polar molecular
90) Identify the type of solid shown in the image.
© C Squared Studios/Getty Images
A) metallic
B) ionic
C) network
D) nonpolar molecular
E) polar molecular
91) Identify the type of solid shown in the image.
A) metallic
B) ionic
C) network
D) molecular
E) amorphous
92) Which substance has the highest melting point?
A) Cu
B) C6H14
C) Rn
D) C (graphite)
E) I2
93) Which substance has the highest melting point?
A) Mn
B) C8H18
C) Ar
D) C (diamond)
E) Br2
94) Which substance has the highest melting point?
A) Mg
B) C5H12
C) Kr
D) SiO2 (silica)
E) Cl2
95) Which substance has the highest melting point?
A) Br2
B) C6H10
C) Ar
D) KBr
E) Cl2
96) Consider the melting point of the following solids. Which of these solids is most likely a molecular solid?
A) SiO2, 1610ºC
B) SiC, 2700ºC
C) BN, 3000ºC
D) KBr, 734ºC
E) GeBr4, 26ºC
97) Consider the melting point of the following solids. Which of these solids is most likely a network solid?
A) SiF4, −90ºC
B) CO2, −57ºC
C) BN, 3000ºC
D) KBr, 734ºC
E) GeBr4, 26ºC
98) The substance shown in the figure must be a solid because you cannot see through it.
©Jim Birk
99) The molecular-level diagram of the substance shown must represent a liquid, since the atoms are not very close to one another.
100) The molecular-level diagram shows the process of evaporation.
101) The molecular-level diagram shows the process of condensation.
102) If there were no intermolecular forces, most matter would be in the gas phase at room temperature.
103) One would expect that since CO is polar, it has a higher boiling point than C6H14.
104) Of the two molecules shown in the figure, one would expect that CO2 has a higher boiling point than NO2 because CO2 is linear and nonpolar.
105) One would expect that water is more viscous than C2H6, due to differences in intermolecular forces.
106) Detergents are used to increase the surface tension of water, so that it will stay in the shape of a droplet.
107) Network covalent substances have the highest melting points of all substances.
108) Calculate the amount of heat energy in kJ required to convert 45.0 g of ice at –15.5°C to steam at 124.0°C. (Cwater = 4.18 J/g°C; Cice = 2.03 J/g°C; Csteam = 2.02 J/g°C; molar heat of fusion of ice = 6.01 × 103 J/mol; molar heat of vaporization of liquid water = 4.07 × 104 J/mol)
109) Calculate the amount of heat energy in kJ required to convert 24.0 g of water at 25.5°C to steam at 124.0°C. (Cwater = 4.18 J/g°C; Csteam = 2.02 J/g°C; molar heat of vaporization of liquid water = 4.07 × 104 J/mol)
110) HCl boils at –85°C and F2 boils at –188°C. Which type of intermolecular force is responsible for the higher boiling point of HCl?
111) CH3OH boils at 64.7°C, and C2H6 boils at –88°C. Which types of intermolecular forces are responsible for the difference in their boiling points?
112) Explain why different liquids have different vapor pressures at a given temperature by filling in the blanks in the following statements: Different liquids have differing amounts of ________. Liquids with ________ intermolecular forces vaporize more easily at a given temperature, and thus will have a ________ vapor pressure than a liquid with ________ intermolecular forces.
113) Explain why a container of liquid can begin to boil with no added heat if the air above the liquid is removed using a vacuum pump by filling in the blanks in the following statements: The ________ of a liquid is the temperature at which its ________ equals the atmospheric pressure on the sample. If the pressure is ________ sufficiently, the vapor pressure of the liquid will be greater than the pressure in the system, and the liquid will begin to boil.
114) What causes water to have a high boiling point, high viscosity, and high surface tension, compared to other liquids?
115) When liquid water is poured onto a flat plate of glass, it spreads out, while liquid mercury forms spherical beads under similar circumstances. Explain the difference in behavior of the two liquids by filling in the blanks in the following statements: The attractions between the water molecules and the glass are ________ than the attractions among the water molecules themselves, so the water spreads out. The attractions among the mercury atoms are ________ than the attractions between the mercury atoms and the glass, so it maintains a spherical shape.
116) What is the boiling point in °C of acetone at 0.8 atm?
117) What is the boiling point in °C of acetone at 1.2 atm?
118) Explain how a pressure cooker works by filling in the blanks in the following statement: A pressure cooker allows the pressure inside the cooker to become ________ than atmospheric pressure, which ________ the boiling point of the water used to cook the food, thus cooking the food ________.