Chapter 13 Intermolecular Forces, Liquids, and Solids

Which of the following molecules can hydrogen bond with itself? 1.1, 2 2.2, 3 3.3, 4 4.1, 2, 3 5.1, 2, 3, 4

Which of the following molecules can hydrogen bond with itself? 1.1, 2 2.2, 3 3.3, 4 4.1, 2, 3 5.1, 2, 3, 4

Arrange the following according to increasing melting point. 1.O 2 < He < I 2 < Kr 2.He < O 2 < I 2 < Kr 3.He < O 2 < Kr < I 2 4.I 2 < Kr < O 2 < He 5.I 2 < Kr < He < O 2 Kr I 2 O 2 He

Arrange the following according to increasing melting point. 1.O 2 < He < I 2 < Kr 2.He < O 2 < I 2 < Kr 3.He < O 2 < Kr < I 2 4.I 2 < Kr < O 2 < He 5.I 2 < Kr < He < O 2 Kr I 2 O 2 He

Arrange the following according to increasing melting point. 1.MgO < H 2 O < CO 2 < O 2 2.O 2 < CO 2 < H 2 O < MgO 3.O 2 < H 2 O < CO 2 < MgO 4.H 2 O < O 2 < MgO < CO 2 5.O 2 < CO 2 < H 2 O < MgO MgO CO 2 O 2 H 2 O

Arrange the following according to increasing melting point. 1.MgO < H 2 O < CO 2 < O 2 2.O 2 < CO 2 < H 2 O < MgO 3.O 2 < H 2 O < CO 2 < MgO 4.H 2 O < O 2 < MgO < CO 2 5.O 2 < CO 2 < H 2 O < MgO MgO CO 2 O 2 H 2 O

Arrange the following according to increasing vapor pressure. 1.NH 3 < I 2 < Br 2 < CH 4 2.I 2 < Br 2 < NH 3 < CH 4 3.NH 3 < CH 4 < I 2 < Br 2 4.NH 3 < I 2 < CH 4 < Br 2 5.CH 4 < NH 3 < Br 2 < I 2 NH 3 I 2 Br 2 CH 4

Arrange the following according to increasing vapor pressure. 1.NH 3 < I 2 < Br 2 < CH 4 2.I 2 < Br 2 < NH 3 < CH 4 3.NH 3 < CH 4 < I 2 < Br 2 4.NH 3 < I 2 < CH 4 < Br 2 5.CH 4 < NH 3 < Br 2 < I 2 NH 3 I 2 Br 2 CH 4

Which does not represent close packing? 1.ABABAB 2.ABCABC 3.ABACBAC 4.AABCABB 5.CACBABC

Which does not represent close packing? 1.ABABAB 2.ABCABC 3.ABACBAC 4.AABCABB 5.CACBABC

Which statement is true? 1.Boiling point ~120°C 2.Boiling point ~95°C 3.Boiling point ~75°C 4.Melting point ~95°C 5.Melting point ~75°C Vapor Pressure (mm Hg) Temperature ( ° C) 0

Which statement is true? 1.Boiling point ~120°C 2.Boiling point ~95°C 3.Boiling point ~75°C 4.Melting point ~95°C 5.Melting point ~75°C Vapor Pressure (mm Hg) Temperature ( ° C) 0

Lead crystallizes in a face-centered cubic unit cell. How many lead atoms are in one unit cell?

Lead crystallizes in a face-centered cubic unit cell. How many lead atoms are in one unit cell?

How many tetrahedral holes are in a face- centered cubic unit cell?

How many tetrahedral holes are in a face- centered cubic unit cell?

Of the following substances, predict which has the highest boiling point based on intermolecular forces. 1.Propane, C 3 H 8 2.Dimethyl ether, CH 3 OCH 3 3.Methyl chloride, CH 3 Cl 4.Acetaldehyde, CH 3 CHO 5.Acetonitrile, CH 3 CN

Of the following substances, predict which has the highest boiling point based on intermolecular forces. 1.Propane, C 3 H 8 2.Dimethyl ether, CH 3 OCH 3 3.Methyl chloride, CH 3 Cl 4.Acetaldehyde, CH 3 CHO 5.Acetonitrile, CH 3 CN

Correct Answer: Each of these molecules has almost the same molecular weight; however, acetonitrile has the largest dipole moment (3.9 D) and hence the largest dipole-dipole forces. Thus it has the highest boiling point. 1.Propane, C 3 H 8 2.Dimethyl ether, CH 3 OCH 3 3.Methyl chloride, CH 3 Cl 4.Acetaldehyde, CH 3 CHO 5.Acetonitrile, CH 3 CN

Of the following substances, predict which has the lowest boiling point based on London dispersion forces. 1.He 2.Ne 3.Ar 4.Kr 5.Xe

Correct Answer: More massive species have more polarizability and stronger London dispersion forces; consequently, amongst the noble gases He has the lowest boiling point. 1.He 2.Ne 3.Ar 4.Kr 5.Xe

Of the following substances, predict which has the highest boiling point based upon intermolecular forces? 1.CH 4 2.H 2 O 3.H 2 S 4.SiH 4 5.H 2 Se N  H ……. O=C

Correct Answer: Of these, only H 2 O has any hydrogen bonding. Hydrogen bonding substantially increases the intermolecular forces, and hence the boiling point. 1.CH 4 2.H 2 O 3.H 2 S 4.SiH 4 5.H 2 Se

Which one of the following phase changes is an exothermic process? 1.Sublimation 2.Vaporization 3.Condensation 4.Melting

Correct Answer: All the other phase-change processes listed are endothermic. 1.Sublimation 2.Vaporization 3.Condensation 4.Melting

How much energy is required to raise the temperature of g ice at 0°C to 10°C?  H fus = 6.01 kJ/mol, heat capacity of water is 75.2 J/mol-K kJ kJ kJ kJ kJ

Correct Answer: There are 100 moles of ice, so the enthalpy of fusion is:  H =(6.01 kJ/mol)(100 mol) = 601 kJ. To raise the water temperature 10°C requires q = (75.2 J/mol-K)(100 mol)(10°C ) = 75.2 kJ. Total energy = 601 kJ +75 kJ = 676 kJ kJ kJ kJ kJ kJ

Temperature Pressure A D C B In the unlabeled phase diagram below, the line segment from A to B separates which two phases? 1.Gas-liquid 2.Liquid-solid 3.Solid-gas

Correct Answer: 1.Gas-liquid 2.Liquid-solid 3.Solid-gas Temperature Pressure A D C B

Quartz is an example of which type of solid: crystalline or amorphous? 1.Crystalline 2.Amorphous

Correct Answer: In quartz, the Si  O bonds are arranged in regular, defined arrays. 1.Crystalline 2.Amorphous

What are the net number of Na + and Cl  ions in the NaCl unit cell represented below? 1.4 Na +, 4 Cl  2.2 Na +, 1 Cl  3.2 Na +, 2 Cl  4.1 Na +, 2 Cl  5.1 Na +, 1 Cl 

Correct Answer: There are 4 Na + resulting from: (1/4 Na + /edge)(12 edges) = 3 Na + (1 Na + /center)(1 center) = 1 Na + There are 4 Cl − resulting from: (1/8 Cl  /corner)(8 corners) = 1 Cl  (1/2 Cl  /face)(6 faces) = 3 Cl  1.4 Na +, 4 Cl  2.2 Na +, 1 Cl  3.2 Na +, 2 Cl  4.1 Na +, 2 Cl  5.1 Na +, 1 Cl 

The NaCl crystal shown below is an example of which type of cubic lattice? 1.Primitive cubic 2.Body-centered cubic 3.Face-centered cubic

Correct Answer: NaCl is an example of a face-centered crystalline lattice. 1.Primitive cubic 2.Body-centered cubic 3.Face-centered cubic

Diamond and graphite are examples of which type of crystalline solids? 1.Molecular 2.Covalent network 3.Ionic 4.Metallic

Correct Answer: Diamond and graphite are both forms of carbon, and consist of a network of covalent bonds (hence covalent network). 1.Molecular 2.Covalent network 3.Ionic 4.Metallic

Correct Answer: Each of these molecules has almost the same molecular weight; however, acetonitrile has the largest dipole moment (3.9 D) and hence the largest dipole-dipole forces. Thus it has the highest boiling point. 1.Propane, C 3 H 8 2.Dimethyl ether, CH 3 OCH 3 3.Methyl chloride, CH 3 Cl 4.Acetaldehyde, CH 3 CHO 5.Acetonitrile, CH 3 CN

Of the following substances, predict which has the lowest boiling point based on London dispersion forces. 1.He 2.Ne 3.Ar 4.Kr 5.Xe

Correct Answer: More massive species have more polarizability and stronger London dispersion forces; consequently, amongst the noble gases He has the lowest boiling point. 1.He 2.Ne 3.Ar 4.Kr 5.Xe

Of the following substances, predict which has the highest boiling point based upon intermolecular forces? 1.CH 4 2.H 2 O 3.H 2 S 4.SiH 4 5.H 2 Se N  H ……. O=C

Correct Answer: Of these, only H 2 O has any hydrogen bonding. Hydrogen bonding substantially increases the intermolecular forces, and hence the boiling point. 1.CH 4 2.H 2 O 3.H 2 S 4.SiH 4 5.H 2 Se

Which one of the following phase changes is an exothermic process? 1.Sublimation 2.Vaporization 3.Condensation 4.Melting

Correct Answer: All the other phase-change processes listed are endothermic. 1.Sublimation 2.Vaporization 3.Condensation 4.Melting

How much energy is required to raise the temperature of g ice at 0°C to 10°C?  H fus = 6.01 kJ/mol, heat capacity of water is 75.2 J/mol-K kJ kJ kJ kJ kJ

Correct Answer: There are 100 moles of ice, so the enthalpy of fusion is:  H =(6.01 kJ/mol)(100 mol) = 601 kJ. To raise the water temperature 10°C requires q = (75.2 J/mol-K)(100 mol)(10°C ) = 75.2 kJ. Total energy = 601 kJ +75 kJ = 676 kJ kJ kJ kJ kJ kJ

Temperature Pressure A D C B In the unlabeled phase diagram below, the line segment from A to B separates which two phases? 1.Gas-liquid 2.Liquid-solid 3.Solid-gas

Correct Answer: 1.Gas-liquid 2.Liquid-solid 3.Solid-gas Temperature Pressure A D C B

Quartz is an example of which type of solid: crystalline or amorphous? 1.Crystalline 2.Amorphous

Correct Answer: In quartz, the Si  O bonds are arranged in regular, defined arrays. 1.Crystalline 2.Amorphous

What are the net number of Na + and Cl  ions in the NaCl unit cell represented below? 1.4 Na +, 4 Cl  2.2 Na +, 1 Cl  3.2 Na +, 2 Cl  4.1 Na +, 2 Cl  5.1 Na +, 1 Cl 

Correct Answer: There are 4 Na + resulting from: (1/4 Na + /edge)(12 edges) = 3 Na + (1 Na + /center)(1 center) = 1 Na + There are 4 Cl − resulting from: (1/8 Cl  /corner)(8 corners) = 1 Cl  (1/2 Cl  /face)(6 faces) = 3 Cl  1.4 Na +, 4 Cl  2.2 Na +, 1 Cl  3.2 Na +, 2 Cl  4.1 Na +, 2 Cl  5.1 Na +, 1 Cl 

The NaCl crystal shown below is an example of which type of cubic lattice? 1.Primitive cubic 2.Body-centered cubic 3.Face-centered cubic

Correct Answer: NaCl is an example of a face-centered crystalline lattice. 1.Primitive cubic 2.Body-centered cubic 3.Face-centered cubic

Diamond and graphite are examples of which type of crystalline solids? 1.Molecular 2.Covalent network 3.Ionic 4.Metallic

Correct Answer: Diamond and graphite are both forms of carbon, and consist of a network of covalent bonds (hence covalent network). 1.Molecular 2.Covalent network 3.Ionic 4.Metallic