Chapter 10 Review Questions

General Chemistry: Atoms First, 2e (McMurry and Fay) Chapter 10 Liquids, Solids, and Phase Changes 10.1 Multiple Choice Questions 1) The bonds in the polyatomic ion CO32– are classified as A) ionic. B) metallic. C) nonpolar covalent. D) polar covalent. Answer: D Diff: 1 Topic: Section 10.2 Kinds of Intermolecular Forces 2) Which covalent bond is the most polar? A) N-F B) C-F C) Cl-F D) F-F Answer: B Diff: 1 Topic: Section 10.2 Kinds of Intermolecular Forces Algo. Option: algorithmic 3) Which has a dipole moment? A) CO2 B) CO32– C) SO2 D) SO42– Answer: C Diff: 1 Topic: Section 10.1 Polar Covalent Bonds and Dipole Moments 4) Which of the following molecules does not have a dipole moment? A) CH2=CH2 B) NH3 C) CH3NH2 D) HCl Answer: A Diff: 1 Topic: Section 10.1 Polar Covalent Bonds and Dipole Moments Algo. Option: algorithmic 1 Copyright © 2014 Pearson Education, Inc. 5) Which of the following should have the largest dipole moment? A) H2(g) B) CO2(g) C) KCl(g) D) CH3F(g) Answer: C Diff: 1 Topic: Section 10.1 Polar Covalent Bonds and Dipole Moments Algo. Option: algorithmic 6) The dipole moment of ClF is 0.88 D, and its bond length is 163 pm. What is the percent ionic character of the Cl-F bond? A) 0.54% B) 7.8% C) 11% D) 25% Answer: C Diff: 2 Topic: Section 10.1 Polar Covalent Bonds and Dipole Moments 7) The dipole moment of BrF is 1.29 D, and its bond length is 178 pm. What is the percent ionic character of the Br-F bond? A) 3.9% B) 8.5% C) 15% D) 33% Answer: C Diff: 2 Topic: Section 10.1 Polar Covalent Bonds and Dipole Moments 8) AgCl is found to have 78.1% ionic character, and its gas phase dipole moment is 11.5 D. What is the distance between the Ag and Cl atoms in gaseous AgCl? A) 9.19 x 10-10 pm B) 14.7 pm C) 307 pm D) 903 pm Answer: C Diff: 2 Topic: Section 10.1 Polar Covalent Bonds and Dipole Moments 2 Copyright © 2014 Pearson Education, Inc. 9) Which has the smallest dipole-dipole forces? A) CH3F B) HCl C) N2 D) CO Answer: C Diff: 1 Topic: Section 10.2 Kinds of Intermolecular Forces Algo. Option: algorithmic 10) Which of the following does not exhibit hydrogen bonding? A) B) C) HF D) HO C OH Answer: A Diff: 1 Topic: Section 10.2 Kinds of Intermolecular Forces 11) Which of the following compounds exhibits hydrogen bonding? A) CH3Cl B) HI C) H3C-O-CH3 D) NH3 Answer: D Diff: 1 Topic: Section 10.2 Kinds of Intermolecular Forces Algo. Option: algorithmic 12) Which of the following exhibits hydrogen bonding? A) OH B) O C) D) HCN Answer: A Diff: 1 Topic: Section 10.2 Kinds of Intermolecular Forces 3 Copyright © 2014 Pearson Education, Inc. 13) Which of the following exhibits ion-dipole forces? A) NaCl(s) B) NaCl(aq) C) Na(s) D) Cl2(g) Answer: B Diff: 2 Topic: Section 10.2 Kinds of Intermolecular Forces 14) Which is expected to have the largest dispersion forces? A) C2H6 B) C8H18 C) N2 D) CO2 Answer: B Diff: 1 Topic: Section 10.2 Kinds of Intermolecular Forces Algo. Option: algorithmic 15) Which substance in each of the following pairs is expected to have the larger dispersion forces? A) Br2 in set I and n-butane in set II B) Br2 in set I and isobutane in set II C) I2 in set I and n-butane in set II D) I2 in set I and isobutane in set II Answer: C Diff: 1 Topic: Section 10.2 Kinds of Intermolecular Forces 4 Copyright © 2014 Pearson Education, Inc. 16) Which of the following compounds exhibits only dipole-dipole intermolecular interactions? A) N2 B) HBr C) CO2 D) H2O Answer: B Diff: 2 Topic: Section 10.2 Kinds of Intermolecular Forces Algo. Option: algorithmic 17) In liquid methanol, CH3OH 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: A Diff: 2 Topic: Section 10.2 Kinds of Intermolecular Forces Algo. Option: algorithmic 18) When a narrow diameter glass tube is inserted into a body of water, water rises in the tube and its surface inside is concave upwards. Which statement, concerning the strength of the intermolecular forces between glass and water molecules compared to those between water molecules, is accurate? A) The forces of attraction between the glass and water are weaker than those in water. B) The forces of attraction between the glass and water are stronger than those in water. C) The forces of attraction between the glass and water are the same as those in water. D) Intermolecular forces are irrelevant to this situation. Answer: B Diff: 2 Topic: Section 10.3 Some Properties of Liquids 19) Which of the intermolecular forces is the most important contributor to the high surface tension shown by water? A) dipole-dipole forces B) dispersion forces C) hydrogen bonding D) ion-dipole forces Answer: C Diff: 2 Topic: Section 10.3 Some Properties of Liquids 5 Copyright © 2014 Pearson Education, Inc. 20) Which of the following is most likely to have the highest viscosity at 25°C? A) C4H10 B) HOCH2CH2OH C) C8H18 D) C2H5NH2 Answer: B Diff: 2 Topic: Section 10.3 Some Properties of Liquids 21) Which is expected to have the highest surface tension at 25°? A) C5H12 B) C6H6 C) C2H5OH D) C3H5(OH)3 Answer: D Diff: 2 Topic: Section 10.3 Some Properties of Liquids 22) The magnitude of the heats of vaporization, fusion and sublimation of a substance reflect the A) density of the substance. B) magnitudes of the boiling and melting points of the substance. C) strength of the covalent bonds between atoms in each molecule of the substance. D) strength of the intermolecular forces of the substance. Answer: D Diff: 1 Topic: Section 10.4 Phase Changes Between Solids, Liquids, and Gases 23) For a particular compound, which is expected to be the largest in general? A) the heat required to raise the temperature of one mole of the gas 10.0°C B) the heat required to raise the temperature of one mole of the liquid 10.0°C C) the molar heat of fusion at the normal melting point D) the molar heat of vaporization at the normal boiling point Answer: D Diff: 3 Topic: Section 10.4 Phase Changes Between Solids, Liquids, and Gases 24) Which of the following phase changes has a positive value for its entropy change? A) boiling water B) formation of raindrops from a cloud C) making dry ice from gaseous CO2 D) making ice cubes from liquid water Answer: A Diff: 2 Topic: Section 10.4 Phase Changes Between Solids, Liquids, and Gases 6 Copyright © 2014 Pearson Education, Inc. 25) For which of the following phase changes is the sign of ΔS negative? A) boiling of water B) formation of snow from water vapor in clouds C) melting of ice cream D) sublimation of I2 Answer: B Diff: 2 Topic: Section 10.4 Phase Changes Between Solids, Liquids, and Gases 26) When a substance melts at its normal melting point, the sign of △H is ________ and the sign of △S of this phase change is ________. A) + , B) - , + C) + , + D) - , Answer: C Diff: 2 Topic: Section 10.4 Phase Changes Between Solids, Liquids, and Gases 27) Ethyl chloride, C2H5Cl, is used as a local anesthetic. It works by cooling tissue as it vaporizes. The heat of vaporization is 26.4 kJ/mol. How much heat could be removed by 10.0 g of ethyl chloride? A) 4.09 kJ B) 170 kJ C) 264 kJ D) 1700 kJ Answer: A Diff: 2 Topic: Section 10.4 Phase Changes Between Solids, Liquids, and Gases Algo. Option: algorithmic 28) Bromine is one of only two elements that is a liquid at room temperature. Bromine has a heat of vaporization of 30.91 kJ/mol and its boiling point is 59°C. What is the entropy of vaporization for bromine? A) -301 J/(mol ∙ K) B) -93.1 J/(mol ∙ K) C) 10.7 J/(mol ∙ K) D) 93.1 J/(mol ∙ K) Answer: D Diff: 2 Topic: Section 10.4 Phase Changes Between Solids, Liquids, and Gases 7 Copyright © 2014 Pearson Education, Inc. 29) CFC-11 (trichlorofluoromethane, CCl3F) has been used for many years as the working fluid in refrigerators. Given its heat of vaporization is 26.88 kJ/mol and its entropy of vaporization is 90.51 J/(mol ∙ K), what is the boiling point of CFC-11? A) -272.9°C B) 0.297°C C) 2.44°C D) 23.8°C Answer: D Diff: 2 Topic: Section 10.4 Phase Changes Between Solids, Liquids, and Gases 30) How much heat is released when 75.0 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 kJ B) 195 kJ C) 228 kJ D) 248 kJ Answer: C Diff: 4 Topic: Section 10.4 Phase Changes Between Solids, Liquids, and Gases Algo. Option: algorithmic 31) For the process: HNO3(g) ⇌ HNO3(l) ΔH° is -39.04 kJ/mol and ΔS° is -111.74 J/(mol ∙ K). What is the normal boiling point of pure HNO3? A) 2.86°C B) 76.2°C C) 270.3°C D) 349.4°C Answer: B Diff: 3 Topic: Section 10.4 Phase Changes Between Solids, Liquids, and Gases 32) When a liquid is heated at its boiling point, the A) covalent bonds are broken, allowing vaporization to occur. B) temperature of the liquid increases. C) temperature of the liquid remains the same as long as any liquid is present. D) temperature of the vapor phase increases. Answer: C Diff: 2 Topic: Section 10.5 Evaporation, Vapor Pressure, and Boiling Point 8 Copyright © 2014 Pearson Education, Inc. 33) As a liquid evaporates at a temperature below its boiling point, the temperature of the liquid A) decreases. B) decreases at low temperatures, but increases at high temperatures. C) increases. D) remains unchanged. Answer: A Diff: 2 Topic: Section 10.5 Evaporation, Vapor Pressure, and Boiling Point 34) Molecules of a liquid can pass into the vapor phase only if the A) liquid has little surface tension. B) molecules have sufficient kinetic energy to overcome the intermolecular forces in the liquid. C) temperature of the liquid is near its boiling point. D) vapor pressure of the liquid is high. Answer: B Diff: 2 Topic: Section 10.5 Evaporation, Vapor Pressure, and Boiling Point 35) The vapor pressure of a pure liquid increases as the A) average kinetic energy of the molecules in the liquid phase decreases. B) intermolecular attractive forces increase. C) temperature of the liquid phase decreases. D) temperature of the liquid phase increases. Answer: D Diff: 2 Topic: Section 10.5 Evaporation, Vapor Pressure, and Boiling Point 36) The normal boiling point occurs when the A) intermolecular forces within the liquid phase are broken. B) temperature of the pure liquid equals the external temperature. C) vapor pressure of a pure liquid equals an external pressure of one atmosphere. D) vapor pressure of the liquid equals the external pressure. Answer: C Diff: 2 Topic: Section 10.5 Evaporation, Vapor Pressure, and Boiling Point 37) Which of the following compounds has the highest boiling point? A) H2O B) HCl C) H2S D) NH3 Answer: A Diff: 1 Topic: Section 10.2 Kinds of Intermolecular Forces Algo. Option: algorithmic 9 Copyright © 2014 Pearson Education, Inc. 38) Which of the following substances has the highest boiling point? A) CH3-CH2-CH2-CH2-CH3 B) Xe C) CH3-CH2-CH3 D) (CH3)4C Answer: A Diff: 3 Topic: Section 10.2 Kinds of Intermolecular Forces 39) Which of the following compounds has the highest boiling point? A) CH3CH2OH B) HOCH2CH2OH C) H3C-O-CH3 D) CH3CH2CH2CH3 Answer: B Diff: 3 Topic: Section 10.2 Kinds of Intermolecular Forces 40) Which of the following has the lowest boiling point? A) Ar B) C) HF D) HCl Answer: A Diff: 3 Topic: Section 10.2 Kinds of Intermolecular Forces 41) Arrange the following in order of increasing boiling point. CH3CH2OH CH3CH2CH3 H3C-O-CH3 CH3CH2NH2 I II III IV A) IV < III < II < I B) II < III < IV < I C) I < IV < III < II D) II < III < I < IV Answer: B Diff: 3 Topic: Section 10.2 Kinds of Intermolecular Forces 10 Copyright © 2014 Pearson Education, Inc. 42) The normal boiling point for HBr is higher than the normal boiling point for HCl. This can be explained by A) larger dipole-dipole forces for HBr. B) larger dispersion forces for HBr. C) larger hydrogen-bond forces for HBr. D) larger dipole-dipole forces, larger dispersion forces, and larger hydrogen-bond forces for HBr. Answer: B Diff: 3 Topic: Section 10.2 Kinds of Intermolecular Forces Algo. Option: algorithmic 43) A kitchen pressure cooker operates at 1.50 atm. The ΔHvap of water is 40.7 kJ/mol. What is the boiling point of water in the pressure cooker? A) 362 K B) 373 K C) 385 K D) 410 K Answer: C Diff: 4 Topic: Section 10.5 Evaporation, Vapor Pressure, and Boiling Point 44) While mercury is very useful in barometers, mercury vapor is toxic. Given that mercury has a ΔHvap of 59.11 kJ/mol and its normal boiling point is 356.7°C, calculate the vapor pressure in mm Hg at room temperature, 25°C. A) 2.68 x 10-3 mm Hg B) 2.99 mm Hg C) 372 mm Hg D) 753 mm Hg Answer: A Diff: 4 Topic: Section 10.5 Evaporation, Vapor Pressure, and Boiling Point 45) Hydroquinone is an antioxidant that is also used as a photographic reducer and developer. The normal boiling point of hydroquinone is 310°C. Calculate the pressure at which hydroquinone will boil at 200°C given that its is 73.38 kJ/mol. A) 1.210 x 10-4 mm Hg B) 1.35 mm Hg C) 22.5 mm Hg D) 757 mm Hg Answer: C Diff: 4 Topic: Section 10.5 Evaporation, Vapor Pressure, and Boiling Point 11 Copyright © 2014 Pearson Education, Inc. 46) The vapor pressure of liquid chloroform, CHCl3, is 400.0 torr at 24.1°C and 100.0 torr at -6.3°C. What is ΔHvap of chloroform? A) 15.3 kJ/mol B) 30.1 kJ/mol C) 57.6 kJ/mol D) 86.7 kJ/mol Answer: B Diff: 4 Topic: Section 10.5 Evaporation, Vapor Pressure, and Boiling Point 47) Solids having no ordered long-range structure are classified as A) amorphous. B) crystalline. C) metallic. D) molecular. Answer: A Diff: 1 Topic: Section 10.6 Kinds of Solids 48) Which of the following forms a molecular solid? A) CaO B) C10H22 C) C(graphite) D) gold Answer: B Diff: 1 Topic: Section 10.6 Kinds of Solids Algo. Option: algorithmic 49) Which of the following statements is not consistent with the properties of a molecular solid? A) a compound that conducts electricity when molten B) a low melting solid C) a solid formed by the combination of two nonmetallic elements D) a solid that is a nonconductor of electricity Answer: A Diff: 1 Topic: Section 10.6 Kinds of Solids 12 Copyright © 2014 Pearson Education, Inc. 50) Which of the following forms an ionic solid? A) Ag B) C7H15NH2 C) RbI D) SO3 Answer: C Diff: 1 Topic: Section 10.6 Kinds of Solids Algo. Option: algorithmic 51) Which of the following is an ionic solid? A) Cl B) N C) D) H Answer: A Diff: 1 Topic: Section 10.6 Kinds of Solids 52) Which of the following is not an ionic solid? A) B) Cl C) N C D) Ba Answer: A Diff: 1 Topic: Section 10.6 Kinds of Solids 53) A crystalline solid of unknown origin forms an aqueous solution that conducts an electrical current. The solid has a high melting point and shatters when struck with a hammer. The solid is likely to be A) a covalent network solid. B) an ionic solid. C) a metallic solid. D) a molecular solid. Answer: B Diff: 1 Topic: Section 10.6 Kinds of Solids 13 Copyright © 2014 Pearson Education, Inc. 54) Which of the following compounds forms a covalent network solid? A) Li B) C (diamond) C) O2 D) CO2 Answer: B Diff: 1 Topic: Section 10.6 Kinds of Solids 55) Which of the following compounds forms a covalent network solid? A) C8H18 B) NO2 C) SiO2 D) SnCl4 Answer: C Diff: 1 Topic: Section 10.6 Kinds of Solids 56) Which type of bonding does Mg form upon solidification? A) covalent network B) ionic C) metallic D) molecular Answer: C Diff: 1 Topic: Section 10.6 Kinds of Solids Algo. Option: algorithmic 57) The wavelength of light used to observe an object must be ________ than the object itself. A) larger B) less than twice C) of higher energy D) of lower energy Answer: B Diff: 1 Topic: Section 10.7 Probing the Structure of Solids: X-Ray Crystallography 58) The structure of a solid can be determined by diffraction of radiation in which region of the electromagnetic radiation spectrum? A) infrared B) microwave C) visible D) X-ray Answer: D Diff: 1 Topic: Section 10.7 Probing the Structure of Solids: X-Ray Crystallography 14 Copyright © 2014 Pearson Education, Inc. 59) How many atoms are in one face-centered cubic unit cell of a metal? A) 1 B) 2 C) 3 D) 4 Answer: D Diff: 2 Topic: Section 10.8 The Packing of Spheres in Crystalline Solids: Unit Cells 60) How many atoms are in one body-centered cubic unit cell of a metal? A) 1 B) 2 C) 3 D) 4 Answer: B Diff: 2 Topic: Section 10.8 The Packing of Spheres in Crystalline Solids: Unit Cells 61) When cubic unit cells stack together, how many unit cells share a common corner? A) 2 B) 4 C) 6 D) 8 Answer: D Diff: 2 Topic: Section 10.8 The Packing of Spheres in Crystalline Solids: Unit Cells 62) How many unit cells share an atom that is on the face of a face-centered cubic unit cell? A) 1 B) 2 C) 4 D) 8 Answer: B Diff: 2 Topic: Section 10.8 The Packing of Spheres in Crystalline Solids: Unit Cells 63) Which type of spherical packing has the most unused space? A) body-centered cubic B) cubic closest-packed C) cubic closest-packed and hexagonal closest-packed D) simple cubic Answer: D Diff: 2 Topic: Section 10.8 The Packing of Spheres in Crystalline Solids: Unit Cells 15 Copyright © 2014 Pearson Education, Inc. 64) Iron crystallizes in a body-centered cubic cell having an edge length of 287 pm. What is the density of iron in g/cm3. A) 1.99 B) 7.85 C) 11.9 D) 15.9 Answer: B Diff: 3 Topic: Section 10.8 The Packing of Spheres in Crystalline Solids: Unit Cells 65) What is the edge length of a face-centered cubic unit cell made up of atoms having a radius of 175 pm? A) 247 pm B) 495 pm C) 700 pm D) 1400 pm Answer: B Diff: 2 Topic: Section 10.8 The Packing of Spheres in Crystalline Solids: Unit Cells Algo. Option: algorithmic 66) Rhodium has a face-centered cubic structure and has a density of 12.4 g/cm3. What is its atomic radius? A) 134 pm B) 268 pm C) 380 pm D) 1070 pm Answer: A Diff: 4 Topic: Section 10.8 The Packing of Spheres in Crystalline Solids: Unit Cells Algo. Option: algorithmic 67) Silver crystallizes in a face-centered cubic structure. What is the edge length of the unit cell if the atomic radius of silver is 144 pm? A) 204 pm B) 288 pm C) 333 pm D) 407 pm Answer: D Diff: 2 Topic: Section 10.8 The Packing of Spheres in Crystalline Solids: Unit Cells Algo. Option: algorithmic 16 Copyright © 2014 Pearson Education, Inc. 68) An element forms a body-centered cubic crystalline substance. The edge length of the unit cell is 287 pm and the density of the crystal is 7.92 g/cm3. Calculate the atomic weight of the substance. A) 45.0 amu B) 48.0 amu C) 56.4 amu D) 63.5 amu Answer: C Diff: 5 Topic: Section 10.8 The Packing of Spheres in Crystalline Solids: Unit Cells 69) Cesium has a radius of 272 pm and crystallizes in a face-centered cubic unit cell. What is the edge length of the unit cell? A) 314 pm B) 385 pm C) 544 pm D) 769 pm Answer: D Diff: 2 Topic: Section 10.7 Probing the Structure of Solids: X-Ray Crystallography Algo. Option: algorithmic 70) Manganese crystallizes in a body-centered cubic structure. What is the coordination number of each atom? A) 4 B) 6 C) 8 D) 12 Answer: C Diff: 1 Topic: Section 10.8 The Packing of Spheres in Crystalline Solids: Unit Cells Algo. Option: algorithmic 71) Cubic closest-packing A) has a body-centered cubic unit cell. B) has a face-centered cubic unit cell. C) has a simple cubic unit cell. D) has the same unit cell as hexagonal closest-packing. Answer: B Diff: 1 Topic: Section 10.8 The Packing of Spheres in Crystalline Solids: Unit Cells 17 Copyright © 2014 Pearson Education, Inc. 72) The highest coordination number for spherical packing is found in the A) body-centered cubic structure. B) simple cubic structure. C) body-centered cubic and face-centered cubic. D) cubic closest-packing and hexagonal closest packing. Answer: D Diff: 1 Topic: Section 10.8 The Packing of Spheres in Crystalline Solids: Unit Cells 73) KCl crystallizes in a cubic unit cell with Cl- ions on each corner and each face. How many K+ ions and Cl- ions are in each unit cell of KCl? A) 1 K+ ion and 1 Cl- ion B) 2 K+ ions and 2 Cl- ions C) 4 K+ ions and 4 Cl- ions D) 8 K+ ions and 8 Cl- ions Answer: C Diff: 2 Topic: Section 10.9 Structures of Some Ionic Solids Algo. Option: algorithmic 74) An ionic compound crystallizes in a unit cell having a face-centered cubic array of anions, X–, and half of the tetrahedral holes filled with metal ions, Mn+ The empirical formula of this ionic compound is A) MX. B) MX2. C) M2X. D) M2X7. Answer: A Diff: 2 Topic: Section 10.9 Structures of Some Ionic Solids 75) An ionic compound crystallizes in a unit cell having a face-centered cubic array of metal ions, Mn+, and all of the tetrahedral holes occupied by anions, X–. The empirical formula of this ionic compound is A) MX. B) MX2. C) M2X. D) M7X4. Answer: B Diff: 2 Topic: Section 10.9 Structures of Some Ionic Solids 18 Copyright © 2014 Pearson Education, Inc. 76) The edge length of a face-centered cubic lattice of NaCl is 564 pm. What is the density of NaCl in g/cm3? A) 0.720 B) 1.08 C) 2.16 D) 4.32 Answer: C Diff: 2 Topic: Section 10.9 Structures of Some Ionic Solids 77) How many Cl- ions are around each K+ ion in KCl, which has a cubic unit cell with Cl- ions on each corner and each face? A) 1 B) 4 C) 6 D) 8 Answer: C Diff: 3 Topic: Section 10.9 Structures of Some Ionic Solids Algo. Option: algorithmic 78) A binary ionic compound, MxAy, crystallizes in a cubic structure that contains eight anions (A) entirely within its unit cell and a cation (M) on each corner and on each face. What is the empirical formula of this compound? A) MA B) MA2 C) M2A D) M4A8 Answer: B Diff: 3 Topic: Section 10.9 Structures of Some Ionic Solids 79) O2 and O3 are ________ of oxygen. A) allotropes B) isomers C) isotopes D) stereomers Answer: A Diff: 1 Topic: Section 10.10 Structures of Some Covalent Network Solids 19 Copyright © 2014 Pearson Education, Inc. 80) Which of the following is not an allotrope of carbon? A) coal B) diamond C) fullerene D) graphite Answer: A Diff: 1 Topic: Section 10.10 Structures of Some Covalent Network Solids 81) The layers of graphite are held together by A) covalent bonds. B) dipole-dipole forces. C) London dispersion forces. D) all of the above Answer: C Diff: 2 Topic: Section 10.10 Structures of Some Covalent Network Solids 82) Diamond is held together by A) covalent bonds. B) dipole-dipole forces. C) London dispersion forces. D) all of the above Answer: A Diff: 2 Topic: Section 10.10 Structures of Some Covalent Network Solids 83) Pencil lead is actually A) fullerene. B) graphite. C) lead. D) silica. Answer: B Diff: 1 Topic: Section 10.10 Structures of Some Covalent Network Solids 84) The critical temperature of a substance is the A) highest temperature at which the liquid phase can exist in equilibrium with the gas phase. B) temperature above which the compound decomposes. C) temperature at which all three phases can exist in equilibrium. D) temperature at which sublimation occurs. Answer: A Diff: 2 Topic: Section 10.11 Phase Diagrams 20 Copyright © 2014 Pearson Education, Inc. 85) Which transition could occur if a solid is heated at a pressure below the triple point pressure? A) condensation B) deposition C) melting D) sublimation Answer: D Diff: 2 Topic: Section 10.11 Phase Diagrams 86) Which transition could occur if a solid is heated at a pressure above the triple point pressure? A) condensation B) deposition C) melting D) sublimation Answer: C Diff: 2 Topic: Section 10.11 Phase Diagrams 87) A supercritical fluid refers to a substance A) above both its critical temperature and its critical pressure. B) at its triple point. C) that is in the liquid crystal state. D) with a viscosity of zero. Answer: A Diff: 2 Topic: Section 10.11 Phase Diagrams 88) The liquid crystal state A) is a liquid in which the molecules tend to assume an overall orientation with respect to each other. B) occurs when a supercritical fluid is rapidly cooled below the critical point. C) occurs when an amorphous solid first begins to melt. D) occurs when the first crystals form in the liquid during freezing. Answer: A Diff: 5 Topic: FYI Liquids Made of Ions? 21 Copyright © 2014 Pearson Education, Inc. 89) In the drawing of acetaldehyde, CH3CHO, the largest partial positive charge (δ+) occurs on A) atom (a). B) atom (b). C) atom (c). D) atom (d). Answer: B Diff: 2 Topic: Conceptual Problems 90) In the drawing of acetaldehyde, CH3CHO, the largest partial negative charge (δ -) occurs on A) atom (a). B) atom (b). C) atom (c). D) atom (d). Answer: C Diff: 2 Topic: Conceptual Problems 91) In the drawing of acetic acid, CH3CO2H, a partial positive charge (δ+) occurs on A) only atom (a). B) only atom (b). C) atoms (a) and (c). D) atoms (b) and (d). Answer: D Diff: 2 Topic: Conceptual Problems 22 Copyright © 2014 Pearson Education, Inc. 92) In the drawing of acetic acid, CH3CO2H, a partial negative charge (δ-) occurs on A) only atom (a). B) only atom (b). C) atoms (a) and (c). D) atoms (b) and (d). Answer: C Diff: 2 Topic: Conceptual Problems 93) Which drawing best accounts for the polarity of water, H2O, and the bond polarities that make a major contribution to the overall molecular polarity? A) drawing (1) B) drawing (2) C) drawing (3) D) drawing (4) Answer: D Diff: 2 Topic: Conceptual Problems 23 Copyright © 2014 Pearson Education, Inc. 94) Which drawing best accounts for the polarity of methanol, CH3OH, and the bond polarities that make a major contribution to the overall molecular polarity? A) drawing (1) B) drawing (2) C) drawing (3) D) drawing (4) Answer: B Diff: 2 Topic: Conceptual Problems 24 Copyright © 2014 Pearson Education, Inc. 95) Which drawing best shows the molecular polarity of methylamine, CH3NH2, and the bond polarities that make a major contribution to the overall molecular polarity? A) drawing (1) B) drawing (2) C) drawing (3) D) drawing (4) Answer: A Diff: 2 Topic: Conceptual Problems 25 Copyright © 2014 Pearson Education, Inc. 96) Which drawing best shows the direction of the dipole moment in H2C=CCl2? A) drawing (1) B) drawing (2) C) drawing (3) D) drawing (4) Answer: C Diff: 2 Topic: Conceptual Problems 26 Copyright © 2014 Pearson Education, Inc. 97) Which best indicates the direction of the dipole moment in formaldehyde, H2C=O? A) drawing (1) B) drawing (2) C) drawing (3) D) drawing (4) Answer: C Diff: 2 Topic: Conceptual Problems 27 Copyright © 2014 Pearson Education, Inc. 98) Which best indicates the direction of the dipole moment in acetone, (CH3)2C=O? A) drawing (1) B) drawing (2) C) drawing (3) D) drawing (4) Answer: B Diff: 2 Topic: Conceptual Problems 28 Copyright © 2014 Pearson Education, Inc. 99) Which drawing best represents hydrogen bonding? A) drawing (1) B) drawing (2) C) drawing (3) D) drawing (4) Answer: C Diff: 2 Topic: Conceptual Problems 29 Copyright © 2014 Pearson Education, Inc. 100) Which drawing below best represents hydrogen bonding methanol, CH3OH? A) drawing (1) B) drawing (2) C) drawing (3) D) drawing (4) Answer: C Diff: 3 Topic: Conceptual Problems 30 Copyright © 2014 Pearson Education, Inc. 101) Which drawing best represents hydrogen bonding in methylamine, CH3NH2? A) drawing (1) B) drawing (2) C) drawing (3) D) drawing (4) Answer: A Diff: 3 Topic: Conceptual Problems 102) If figure (1) represents the vapor pressure of water at 25°C, which figure represents the vapor pressure of water at 45°C? A) figure (2) B) figure (3) C) figure (4) Answer: B Diff: 3 Topic: Conceptual Problems 31 Copyright © 2014 Pearson Education, Inc. 103) If figure (1) represents the vapor pressure of water at 25°C in a 1 liter container, which figure represents the vapor pressure of water at 25°C in a 2 liter container? A) figure (2) B) figure (3) C) figure (4) Answer: B Diff: 2 Topic: Conceptual Problems 104) If figure (1) represents the vapor pressure of water at 25°C, which figure represents the vapor pressure of ethanol, CH3CH2OH at 25°C? A) figure (2) B) figure (3) C) figure (4) Answer: B Diff: 2 Topic: Conceptual Problems 105) If figure (1) represents the vapor pressure of diethyl ether, CH3CH2OCH2CH3, at 25°C, which figure represents the vapor pressure of ethanol at 25°C? A) figure (2) B) figure (3) C) figure (4) Answer: C Diff: 2 Topic: Conceptual Problems 32 Copyright © 2014 Pearson Education, Inc. 106) If figure (1) represents the vapor pressure of water, at 25°C, which figure represents the vapor pressure of mercury at 25°C? A) figure (2) B) figure (3) C) figure (4) Answer: C Diff: 2 Topic: Conceptual Problems The plots below represent vapor pressure vs. temperature curves for diethyl ether, ethanol, mercury, and water, not necessarily in that order. 107) Based on the relative strengths of the intermolecular forces of attraction of each substance, which is the most likely vapor pressure vs. temperature curve for diethyl ether? A) curve (a) B) curve (b) C) curve (c) D) curve (d) Answer: A Diff: 2 Topic: Conceptual Problems 108) Based on the relative strengths of the intermolecular forces of attraction of each substance, which is the most likely vapor pressure vs. temperature curve for ethanol? A) curve (a) B) curve (b) C) curve (c) D) curve (d) Answer: B Diff: 2 Topic: Conceptual Problems 33 Copyright © 2014 Pearson Education, Inc. 109) Based on the relative strengths of the intermolecular forces of attraction of each substance, which is the most likely vapor pressure vs. temperature curve for mercury? A) curve (a) B) curve (b) C) curve (c) D) curve (d) Answer: D Diff: 2 Topic: Conceptual Problems 110) Based on the relative strengths of the intermolecular forces of attraction of each substance, which is the most likely vapor pressure vs. temperature curve for water? A) curve (a) B) curve (b) C) curve (c) D) curve (d) Answer: C Diff: 2 Topic: Conceptual Problems 111) From the plot of vapor pressure as a function of temperature shown below, the normal boiling point for tert-butyl alcohol is approximately A) 0°C. B) 40°C. C) 85°C. D) 100°C. Answer: C Diff: 2 Topic: Conceptual Problems 34 Copyright © 2014 Pearson Education, Inc. The picture shown below represents a two-dimensional lattice of atoms M and X. 112) Which of the areas designated A, B, and C are smallest repeating units, analogous to twodimensional unit cells? A) only A B) only B C) only C D) A, B, or C Answer: D Diff: 2 Topic: Conceptual Problems 113) What is the formula of the compound formed from M and X? A) MX B) MX2 C) MX3 D) MX4 Answer: A Diff: 2 Topic: Conceptual Problems 114) Identify the packing in the figure shown below. A) body-centered cubic B) cubic closest packed (face-centered cubic) C) hexagonal closest packed D) simple cubic Answer: B Diff: 2 Topic: Conceptual Problems 35 Copyright © 2014 Pearson Education, Inc. 115) Identify the packing in the figure shown below. A) body-centered cubic B) cubic closest packed (face-centered cubic) C) hexagonal closest packed D) simple cubic Answer: D Diff: 2 Topic: Conceptual Problems 116) Identify the packing in the figure shown below. A) body-centered cubic B) cubic closest packed (face-centered cubic) C) hexagonal closest packed D) simple cubic Answer: C Diff: 2 Topic: Conceptual Problems 117) Identify the packing in the figure shown below. A) body-centered cubic B) cubic closest packed (face-centered cubic) C) hexagonal closest packed D) simple cubic Answer: A Diff: 2 Topic: Conceptual Problems 36 Copyright © 2014 Pearson Education, Inc. A certain mineral crystallizes in the cubic unit cell shown below. 118) What kind of packing do the anions adopt? A) body-centered cubic B) cubic closest packed (face-centered cubic) C) hexagonal closest packed D) simple cubic Answer: B Diff: 2 Topic: Conceptual Problems 119) How many cations and how many anions are in the unit cell? A) 4 cations and 4 anions B) 4 cations and 8 anions C) 4 cations and 14 anions D) 8 cations and 4 anions Answer: A Diff: 2 Topic: Conceptual Problems 37 Copyright © 2014 Pearson Education, Inc. 120) A certain mineral crystallizes in the cubic unit cell shown below. M represents the cations and A represents the anions. What is the empirical formula of the mineral? A) MA B) MA2 C) M2A D) M4A4 Answer: A Diff: 2 Topic: Conceptual Problems A certain mineral, MxM'yAz, crystallizes in the cubic unit cell shown below. M and M' represent cations and A represents the anions. 121) How many cations M are in the unit cell? A) 1 B) 2 C) 4 D) 8 Answer: A Diff: 3 Topic: Conceptual Problems 38 Copyright © 2014 Pearson Education, Inc. 122) How many anions are in the unit cell? A) 1 B) 2 C) 3 D) 6 Answer: C Diff: 3 Topic: Conceptual Problems 123) What is the empirical formula of the mineral? A) MM'A B) MM'A3 C) M2M'A3 D) M8M'A6 Answer: B Diff: 3 Topic: Conceptual Problems 124) If cation M has a 2+ charge and anion A has a 2- charge, what is the oxidation state of cation M'? A) +1 B) +2 C) +3 D) +4 Answer: D Diff: 3 Topic: Conceptual Problems 39 Copyright © 2014 Pearson Education, Inc. 125) Consider a compound that undergoes sublimation at 125°C and a pressure of one atm. Which of the following could be a heating curve appropriate for heating the compound from 100°C to 150°C? A) see graph a B) see graph b C) see graph c D) see graph d Answer: B Diff: 2 Topic: Conceptual Problems 40 Copyright © 2014 Pearson Education, Inc. Use the diagram below to answer the following questions. 126) According to the diagram, the solid phase of this substance A) has the same density as the liquid phase. B) is less dense than water. C) is less dense than the liquid phase. D) is more dense than the liquid phase. Answer: D Diff: 2 Topic: Conceptual Problems 127) Melting occurs along the A) AC line. B) CB line. C) CD line. D) all of the above Answer: B Diff: 2 Topic: Conceptual Problems 128) The solid and liquid phases can exist in equilibrium along line A) AC. B) CB. C) CD. D) BD. Answer: B Diff: 2 Topic: Conceptual Problems 41 Copyright © 2014 Pearson Education, Inc. 129) The temperature and pressure at which all three phases can coexist in equilibrium is A) 0.25 atm and 110°C. B) 1.0 atm and 140°C. C) 1.25 atm and 300°C. D) 0.45 atm and 130°C. Answer: D Diff: 2 Topic: Conceptual Problems 130) From the phase diagram above, the minimum pressure at which this substance can exist in the liquid phase is A) 0.25 atm. B) 0.45 atm. C) 1.0 atm. D) 1.2 atm. Answer: B Diff: 2 Topic: Conceptual Problems 131) The normal boiling point of this substance is approximately A) 25°C. B) 140°C. C) 300°C. D) 350°C. Answer: C Diff: 2 Topic: Conceptual Problems 132) What phases can be present at 200°C and 0.75 atm pressure? A) only the vapor phase B) only the liquid phase C) only the solid phase D) both the solid and vapor phases Answer: B Diff: 2 Topic: Conceptual Problems 133) What phase changes occur when the temperature is held constant at 140°C and the pressure is increased from 0.25 atm to 1.4 atm? A) gas → liquid → solid B) gas → solid → liquid C) liquid → solid → gas D) solid → liquid → vapor Answer: A Diff: 2 Topic: Conceptual Problems 42 Copyright © 2014 Pearson Education, Inc. 134) What phase changes occur when the pressure is held constant at 0.25 atm and the temperature increases from 100°C to 300°C? A) liquid → gas B) solid → gas C) solid → liquid D) solid → liquid → gas Answer: B Diff: 2 Topic: Conceptual Problems The phase diagram of a substance is shown below. 135) The approximate normal boiling point of this substance is A) 180 K. B) 190 K. C) 300 K. D) 430 K. Answer: C Diff: 2 Topic: Conceptual Problems 136) The approximate normal melting point of this substance is A) 100 K. B) 190 K. C) 300 K. D) 430 K. Answer: B Diff: 2 Topic: Conceptual Problems 43 Copyright © 2014 Pearson Education, Inc. 137) What is the physical phase of the substance at T = 100 K and P = 0.1 atm? A) gas B) liquid C) solid D) supercritical fluid Answer: C Diff: 2 Topic: Conceptual Problems 138) What is the physical phase of the substance at T = 225 K and P = 1.1 atm? A) gas B) liquid C) solid D) supercritical fluid Answer: B Diff: 2 Topic: Conceptual Problems 139) What is the physical phase of the substance at T = 400 K and P = 2.0 atm? A) gas B) liquid C) solid D) supercritical fluid Answer: A Diff: 2 Topic: Conceptual Problems 10.2 Algorithmic Questions 1) Which covalent bond is the most polar? A) N-F B) C-F C) Cl-F D) F-F Answer: B Diff: 1 Topic: Section 10.1 Polar Covalent Bonds and Dipole Moments 2) Which of the following should have the largest dipole moment? A) F2(g) B) BCl3(g) C) KBr(g) D) CH3I(g) Answer: C Diff: 1 Topic: Section 10.1 Polar Covalent Bonds and Dipole Moments 44 Copyright © 2014 Pearson Education, Inc. 3) Which of the following molecules does not have a dipole moment? A) C2H2 B) H2O C) CH3CH2OH D) HI Answer: A Diff: 1 Topic: Section 10.1 Polar Covalent Bonds and Dipole Moments 4) Which has the smallest dipole-dipole forces? A) CH3Cl B) HBr C) O2 D) NO Answer: C Diff: 1 Topic: Section 10.2 Kinds of Intermolecular Forces 5) Which is expected to have the largest dispersion forces? A) C3H8 B) C12H26 C) F2 D) Be Cl2 Answer: B Diff: 1 Topic: Section 10.2 Kinds of Intermolecular Forces 6) Which of the following compounds exhibits hydrogen bonding? A) CH3Cl B) HI C) CH3OCH3 D) NH3 Answer: D Diff: 1 Topic: Section 10.2 Kinds of Intermolecular Forces 7) Which of the following compounds has the highest boiling point? A) H2O B) H Cl C) H2S D) N H3 Answer: A Diff: 1 Topic: Section 10.2 Kinds of Intermolecular Forces 45 Copyright © 2014 Pearson Education, Inc. 8) 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: A Diff: 2 Topic: Section 10.2 Kinds of Intermolecular Forces 9) Which of the following compounds exhibits only dispersion and dipole-dipole intermolecular interactions? A) H2 B) HI C) CO2 D) CH3NH2 Answer: B Diff: 2 Topic: Section 10.2 Kinds of Intermolecular Forces 10) The normal boiling point for H2Te is higher than the normal boiling point for H2Se . This can be explained by A) larger dipole-dipole forces for H2Te . B) larger dispersion forces for H2Te . C) larger hydrogen-bond forces for H2Te . D) larger dipole-dipole forces, larger dispersion forces, and larger hydrogen-bond forces for H2Te . Answer: B Diff: 2 Topic: Section 10.5 Evaporation, Vapor Pressure, and Boiling Point 11) 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 kJ B) 341 kJ C) 528 kJ D) 3410 kJ Answer: A Diff: 2 Topic: Section 10.4 Phase Changes Between Solids, Liquids, and Gases 46 Copyright © 2014 Pearson Education, Inc. 12) 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 kJ B) 273 kJ C) 319 kJ D) 347 kJ Answer: C Diff: 3 Topic: Section 10.4 Phase Changes Between Solids, Liquids, and Gases 13) Which of the following forms a molecular solid? A) NH4NO3 B) C6H4Cl2 C) SiO2 D) copper Answer: B Diff: 1 Topic: Section 10.6 Kinds of Solids 14) Which of the following forms an ionic solid? A) Ag B) C7H15NH2 C) Rb I D) S O3 Answer: C Diff: 1 Topic: Section 10.6 Kinds of Solids 15) Which type of bonding does Sr form upon solidification? A) covalent network B) ionic C) metallic D) molecular Answer: C Diff: 1 Topic: Section 10.6 Kinds of Solids 47 Copyright © 2014 Pearson Education, Inc. 16) What is the edge length of a face-centered cubic unit cell made up of atoms having a radius of 128 pm? A) 181 pm B) 362 pm C) 512 pm D) 1020 pm Answer: B Diff: 3 Topic: Section 10.8 The Packing of Spheres in Crystalline Solids: Unit Cells 17) Nickel has a face-centered cubic structure and has a density of 8.90 g/cm3. What is its atomic radius? A) 125 pm B) 249 pm C) 353 pm D) 997 pm Answer: A Diff: 3 Topic: Section 10.8 The Packing of Spheres in Crystalline Solids: Unit Cells 18) A certain metal crystallizes in a face-centered cubic structure. What is the edge length of the unit cell if the atomic radius of the metal is 144 pm? A) 204 pm B) 288 pm C) 333 pm D) 407 pm Answer: D Diff: 3 Topic: Section 10.8 The Packing of Spheres in Crystalline Solids: Unit Cells 19) 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 pm B) 385 pm C) 544 pm D) 628 pm Answer: D Diff: 3 Topic: Section 10.8 The Packing of Spheres in Crystalline Solids: Unit Cells 48 Copyright © 2014 Pearson Education, Inc. 20) Lithium crystallizes in a body-centered cubic structure. What is the coordination number of each atom? A) 4 B) 6 C) 8 D) 12 Answer: C Diff: 1 Topic: Section 10.8 The Packing of Spheres in Crystalline Solids: Unit Cells 21) NaCl 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 NaCl? A) 1 Na+ ion and 1 Cl- ion B) 2 Na+ ions and 2 Cl- ions C) 4 Na+ ions and 4 Cl- ions D) 8 Na+ ions and 8 Cl- ions Answer: C Diff: 2 Topic: Section 10.9 Structures of Some Ionic Solids 22) 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) 1 B) 4 C) 6 D) 8 Answer: C Diff: 2 Topic: Section 10.9 Structures of Some Ionic Solids 10.3 Short Answer Questions 1) The bonds in the polyatomic ion NO3– are classified as Answer: polar covalent. Diff: 2 Topic: Section 10.1 Polar Covalent Bonds and Dipole Moments 2) In the molecule BF3 there is a δ+ charge on the ________ atom and a δ– charge on the ________ atom. Answer: boron, fluorine Diff: 2 Topic: Section 10.2 Kinds of Intermolecular Forces 49 Copyright © 2014 Pearson Education, Inc. 3) The intermolecular forces formed when NaCl is dissolved in water are ________ forces. Answer: ion-dipole Diff: 2 Topic: Section 10.2 Kinds of Intermolecular Forces 4) The intermolecular forces responsible for CH3CH2OH being at liquid at 20°C are ________ bonds. Answer: hydrogen Diff: 2 Topic: Section 10.2 Kinds of Intermolecular Forces 5) Helium can be liquefied when He atoms are attracted to one another by intermolecular ________ forces. Answer: dispersion (or London dispersion) Diff: 2 Topic: Section 10.2 Kinds of Intermolecular Forces 6) Of C2H5OH and C3H5(OH)3 the one expected to have the higher viscosity is ________, and the one expected to have the higher surface tension is ________. Answer: C3H5(OH)3, C3H5(OH)3 Diff: 2 Topic: Section 10.3 Some Properties of Liquids 7) The phase change H2(g) → H2(s) is called ________, and the enthalpy change, △H, for this phase change has a ________ sign. Answer: deposition, negative (–) Diff: 2 Topic: Section 10.4 Phase Changes Between Solids, Liquids, and Gases 8) Of C2H5OH and C3H5(OH)3 the one expected to have the higher vapor pressure is ________, and the one expected to have the higher boiling point is ________. Answer: C2H5OH, C3H5(OH)3 Diff: 2 Topic: Section 10.5 Evaporation, Vapor Pressure, and Boiling Point 9) The solids formed by K, K2O2, SiO2, and O2 are classified as ________, ________, ________, and ________, respectively. Answer: metallic, ionic, covalent network, molecular Diff: 2 Topic: Section 10.6 Kinds of Solids 50 Copyright © 2014 Pearson Education, Inc. 10) Ni has a face-centered unit cell. The number of Ni atoms in the unit cell is ________. Answer: four Diff: 3 Topic: Section 10.8 The Packing of Spheres in Crystalline Solids: Unit Cells 51 Copyright © 2014 Pearson Education, Inc.