1. Based on intermolecular interactions, which of the following should have the highest boiling point?
   1. CH₄
   2. CHCl₃
   3. H₂S
   4. CH₃OH

2. What is the typical range of strengths of hydrogen bonds?
   1. 5 - 25 kJ per mole of bonds
   2. 5 - 25 kJ per molecule
   3. 500 kJ per mole of bonds
   4. 1 - 2 kJ per mole of bonds
   5. less than all the above

3. Hydrogen bonding is unimportant in
   1. ice formation
   2. the liquid properties of water
   3. DNA structure
   4. liquid CH₄
   5. liquid HF

4. Which one of the following statements is incorrect?
   1. Dispersion (London) forces are the weakest type of intermolecular interactions.
   2. The strong intermolecular attractions in H₂O result from hydrogen bonding.
   3. The boiling point of H₂S is lower than H₂O.
   4. The boiling point of non-polar substances tends to decrease with increasing molecular weight.

5. How many atoms per unit cell are there in each of the following cubic lattice types?

   	simple cubic	body-centered cubic	face-centered cubic
   (a)	8	6	12
   (b)	1	2	4
   (c)	1	2	6
   (d)	6	8	14

6. Which of the species below does not exhibit hydrogen bonding?
   1. C₂H₆
   2. NH₃
   3. HF
   4. H₂O
   5. C₂H₅OH

7. Which of the following phase diagrams is consistent with the sublimation of a solid at room temperature (22^oC) and atmospheric pressure?
   

8. What type of attractive forces are being overcome when liquid oxygen boils at 90 K?
   1. ionic bonds
   2. dipole-dipole forces
   3. covalent bonds
   4. dispersion forces
   5. hydrogen bonds

9. What is the coordination number of each sphere in a three dimensional body-centered cubic array of equal-sized spheres?
   1. 4
   2. 6
   3. 8
   4. 12
   5. 16

10. Covalent bonds are the only type of bond or intermolecular forces in:
    1. KF(s).
    2. CO₂(s).
    3. H₂O(s).
    4. NH₄NO₂(s).
    5. C(diamond).

11. The density of silver is 10.5 g/cm³ and this metal crystallizes in the FCC structure. Assuming that nearest neighbor atoms are in contact, what is the atomic radius of Ag?
    1. 5.76 Angstroms
    2. 2.88 Angstroms
    3. 2.29 Angstroms
    4. 1.44 Angstroms
    5. 1.02 Angstroms

12. A white substance melts with some decomposition at 730^oC. As a solid, it is a nonconductor of electricity but it dissolves in water to form a conducting solution. The white substance is:
    1. a covalent network solid.
    2. an ionic solid.
    3. a molecular solid.
    4. a metallic solid.
    5. solid Ar.

13. Which of the following elements has the highest boiling point?
    1. He
    2. F₂
    3. Ne
    4. Br₂
    5. Ar

14. Which of the following shows a hydrogen bonding interaction?
    1. NH₃
    2. CH₄
    3. BH₃
    4. SiH₄
    5. GeH₄

15. Methanol, CH₃OH (bp: 65^oC), boils nearly 230^o higher than methane, CH₄ (bp: -164^oC). What intermolecular forces are responsible for the higher boiling point of methanol?
    1. dispersion forces
    2. hydrogen bonds
    3. induced dipole-induced dipole
    4. ion-dipole
    5. dipole-induced dipole

16. The unit cell of a material has calcium ions at the corners, oxide ions in faces, and transition metal, M, in center. The empirical formula is:
    
    1. CaMO₂
    2. CaMO₃
    3. Ca₄MO₆
    4. Ca₈MO₃
    5. Ca₈MO₆

17. KCl has the same structure as NaCl. If the volume of the unit cell is 247.7 cubic Angstroms, what is the distance between adjacent K⁺ and Cl^- centers?
    1. 1.24 Angstroms
    2. 2.48 Angstroms
    3. 3.14 Angstroms
    4. 3.63 Angstroms
    5. 6.28 Angstroms

18. Fe crystallizes in a body-centered cubic lattice. The density of iron is 7.86 g/cm³. The atomic radius of iron is: [1 Angstrom = 10^-10 M = 10^-8 cm]
    1. 1.24 Angstrom
    2. 2.48 Angstrom
    3. 0.62 Angstrom
    4. 2.02 Angstrom
    5. 0.717 Angstrom

19. The number of unit cells that share an atom represented by the filled circle in the diagram below is:
    
    1. 1
    2. 2
    3. 4
    4. 8
    5. 16

20. Aluminum crystallizes in a face-centered cubic lattice. Which of the following statements is false if r denotes radius of aluminum?
    
    1. The unit cell contains 4 Al atoms.
    2. The unit cell contains 1 octahedral hole.
    3. The face diagonal has length 4r.
    4. The volume occupied by Al in the unit cell is (16 r³/3).
    5. The Al atoms are closest packed.

21. The sum of the first two ionization energies of Ca is 1735.2 kJ mol^-1. Nevertheless, the Born-Haber cycle shows that CaCl₂(s) is a stable ionic material because:
    1. the ionization of calcium is highly exothermic.
    2. the atomization (sublimation) of calcium is endothermic.
    3. chloride has an electron affinity so much greater than the ionization energies of calcium.
    4. the lattice energy more than compensates for the ionization energies.
    5. all of the above are true.

22. The figure depicts the unit cell for a compound containing atoms A (filled circles) and B (open circles). The empirical formula is:
    
    1. AB
    2. AB₂
    3. A₂B
    4. A₆B
    5. A₁₂B₂
    The next three questions refer to 4 liquids, all of which have the molecular formula C₄H₁₀O and which have the following boiling points: A (117.5^oC); B (82.9^oC); C (34.6^oC); D (99.5^oC).

23. The liquid likely to have the highest vapor pressure at 25^oC is:
    1. A
    2. B
    3. C
    4. D
    5. All four substances would have the same vapor pressure since they have the same molecular weight.

24. The intermolecular attractive forces of these are likely to be ordered:
    1. A > D > B > C
    2. B > D > A > C
    3. C > B > D > A
    4. D > C > B > A
    5. none of the above

25. Given the structural isomers below, the one most likely to be liquid C is:
    

26. What pressure would be required to liquify (or condense) a sample of water vapor at 500^oC?
    
    1. 0.0060 atm
    2. 1.00 atm
    3. 218 atm
    4. some pressure higher than 218 atm but which cannot be determined from the phase diagram
    5. no amount of pressure can bring about the change of H₂O vapor to liquid at 500^oC

27. Drops of water and ethanol are placed on a warm stove, and the ethanol drop is seen to evaporate more rapidly. The graph below includes the vapor pressures of ethanol and water. Which curve corresponds to ethanol?
    
    1. A
    2. B
    3. C
    4. D
    5. none of the above

28. Silver crystallizes with a face-centered cubic unit cell. The radius of a silver atom is 0.144 nm. Calculate the density of solid silver.
    1. 25.0 g/cm³
    2. 20.0 g/cm³
    3. 15.6 g/cm³
    4. 10.6 g/cm³
    5. 5.3 g/cm³

29. Which substance would have the strongest hydrogen bonding?
    1. CHCl₃
    2. HBr
    3. H₂O
    4. H₂S
    5. H₂Se

30. Which of the following compounds feature intermolecular bonding in the liquid or solid state?
    1. argon
    2. diamond
    3. water
    4. sodium chloride
    5. none of these

31. Which force makes the most important contribution to the lattice energy of solid argon?
    1. metallic bonding
    2. hydrogen bonding
    3. ionic bonding
    4. covalent bonding
    5. van der Waals forces

32. The key bonding property that yields the characteristic properties of metals is:
    1. -bonding.
    2. delocalized bonding caused by partly filled conduction bands.
    3. a filled conduction band.
    4. ionic bonding.
    5. van der Waals forces.

33. The increasing vapor pressure caused by heating a liquid is due to:
    1. increased intermolecular interactions.
    2. increasing potential energy of molecules.
    3. increasing kinetic energy of molecules.
    4. decreasing surface tension.
    5. weaker solvation.

34. The triple point is:
    1. the point in a phase diagram where the solid, liquid, and gas phases of a substance coexist at equilibrium.
    2. the point where all three phases are unstable.
    3. three places in a phase diagram where the solid, liquid and gas can coexist.
    4. a three-dimensional phase diagram.
    5. a rare play in baseball.

35. Decreasing the external pressure will:
    1. increase the vapor pressure of a liquid.
    2. markedly decrease the freezing point of a liquid.
    3. increase the boiling point of a liquid.
    4. decrease the boiling point of a liquid.
    5. weaken the intermolecular forces in a liquid.

36. Covalent crystals have:
    1. higher melting points than molecular crystals.
    2. lower melting points than molecular crystals.
    3. discrete molecules linked by van der Waals forces.
    4. hydrogen bonding.
    5. always excellent electrical conductivity.

37. Metals have:
    1. an unfilled conduction band.
    2. no conduction band.
    3. a partly filled conduction band.
    4. an energy gap between filled valence band and unfilled conduction band.
    5. only ionic bonding.

38. Which of the following statements is FALSE?
    1. Water boils at a lower temperature atop Mt. Everest than in Lafayette, IN.
    2. Ice has a lower density than liquid water.
    3. The vapor pressure of a liquid is lower than the external pressure at temperatures below its boiling point.
    4. A phase diagram is a pressure-temperature plot which outlines the P-T regions of stability of a molecule in its solid, liquid and gaseous forms.
    5. None of the above.

39. Choose the INCORRECT statement from the following:
    1. Hexagonal closest packed (hcp) and cubic close packed (ccp) structures have coordination numbers of 12 and 6, respectively.
    2. hcp and ccp structures involve ABABAB and ABCABCABC stacking, respectively.
    3. hcp and ccp structures involve the same net packing density.
    4. Metals can crystallize in either hcp or ccp structures, depending on the element.
    5. Some metals form body-centered cubic structures.

40. Which of the following statements about liquids is NOT true?
    1. liquids assume the shape of the container
    2. liquids assume the volume of the container
    3. liquids are virtually incompressible
    4. diffusion of liquids is slow
    5. liquids flow readily

41. What happens to molecules in a liquid when the liquid is heated and vapor starts to form?
    1. the intramolecular forces between liquid molecules are disrupted
    2. the intermolecular forces between liquid molecules are disrupted
    3. kinetic energy is removed from the system
    4. London forces become stronger
    5. surface tension increases, which causes beading up, then boiling

42. Which of the following has the lowest boiling point?
    1. F₂
    2. Cl₂
    3. Br₂
    4. I₂

43. Which of the following has the strongest intermolecular forces?
    1. O₂
    2. Ar
    3. CH₄
    4. HF
    5. HBr

44. Which of the following statements best explains why diamond (carbon) has a higher melting point than dry ice (CO₂)?
    1. because carbon atoms in diamond are held together by a network of covalent bonds
    2. because CO₂ molecules are held together by dipole - dipole forces
    3. the electrostatic attractions in CO₂ are not as strong as those in diamond (carbon)
    4. the dispersion forces in diamond are greater than in CO₂
    5. all of the above

Answers

1. D
2. A
3. D
4. D
5. B
6. A
7. C
8. D
9. C
10. E
11. D
12. B
13. D
14. A
15. B
16. B
17. C
18. A
19. D
20. B
21. D
22. A
23. C
24. A
25. A
26. E
27. A
28. D
29. C
30. C
31. E
32. B
33. C
34. A
35. D
36. A
37. C
38. E
39. A
40. B
41. B
42. A
43. D
44. A