Choose the correct answer for each question.

1. The only intermolecular forces existing between oxygen molecules are:

   1.   ?    permanent dipole forces
   2.   ?    hydrogen bonding forces
   3.   ?    London dispersion forces
   4.   ?    ion-ion attractive forces
   5.   ?    nuclear forces

2. Which of the following substances will have the greatest vapor pressure at 0°C?

   1.   ?    NaCl
   2.   ?    H₂O
   3.   ?    NH₃
   4.   ?    CH₄
   5.   ?    H₂O and NH₃

3. Place the following in order of increasing strength:
   
   

   1. hydrogen bonding 2. covalent bonding 3. London dispersion forces

   1.   ?    1, 2, 3
   2.   ?    3, 2, 1
   3.   ?    1, 3, 2
   4.   ?    2, 1, 3
   5.   ?    3, 1, 2

4. Which of the following hydrocarbons has the highest boiling point?

   1.   ?    CH₄
   2.   ?    C₂H₆
   3.   ?    C₃H₈
   4.   ?    C₄H₁₀
   5.   ?    These are all gases and do not boil

5. A metal has crystallized with a face-centered cubic lattice. The edge of the unit cell is 366 pm. What is the diameter of the metal atom?

   1.   ?    518 pm
   2.   ?    259 pm
   3.   ?    267912 pm
   4.   ?    0.0296 pm
   5.   ?    3.98 x 10^-5 pm

6. For a solution in a closed container at equilibrium, which of the following pairs represent processes that must be occuring at equal rates?

   1.   ?    evaporation and crystallization
   2.   ?    fusion and boiling
   3.   ?    evaporation and sublimation
   4.   ?    crystallization and sublimation
   5.   ?    evaporation and condensation

7. 
   
   The normal boiling point of X is most likely:

   1.   ?    22°C
   2.   ?    28°C
   3.   ?    50°C
   4.   ?    80°C
   5.   ?    90°C

8. 
   
   At a pressure of 1.3 atm and 20°C, compound X exists as:

   1.   ?    a solid only
   2.   ?    a solid and a liquid
   3.   ?    a liquid and a gas
   4.   ?    a solid and a gas
   5.   ?    a liquid only

9. 
   
   The triple point of compound X occurs at a temperature of:

   1.   ?    -10°C
   2.   ?    23°C
   3.   ?    50°C
   4.   ?    80°C
   5.   ?    29°C

10. 
    
    As the pressure increases, the melting point of compound X will:

    1.   ?    increase
    2.   ?    decrease
    3.   ?    stay the same
    4.   ?    increase and then decrease
    5.   ?    decrease and then increase

11. An example of an amorphous solid is:

    1.   ?    ice
    2.   ?    quartz
    3.   ?    plastic
    4.   ?    diamond
    5.   ?    gold

12. Buckminsterfullerene is one of the allotropic forms of:

    1.   ?    silicon
    2.   ?    semimetals
    3.   ?    oxygen
    4.   ?    carbon
    5.   ?    steel

13. Which of the following statements are false?
    
    

    1. Liquids with large intermolecular forces tend to have very low boiling points 2. Liquids with large intermolecular forces tend to have considerable surface tension 3. When a substance changes from a solid to a liquid, the molecules remain intact 4. The hardness of diamond is due to strong dipole-dipole attraction

    1.   ?    1 and 3
    2.   ?    2 and 4
    3.   ?    3 and 4
    4.   ?    1 and 4
    5.   ?    2 and 3

14. Which of the following is not an endothermic process?

    1.   ?    crystallization
    2.   ?    vaporization
    3.   ?    melting
    4.   ?    sublimation
    5.   ?    combustion

15. How much energy is needed to convert 50.0 g of ice at -5.00°C to water at 25°C?
    

    
    
    • Specific heat(ice) = 2.10 J/(g°C)
      
    • Specific heat(water) = 4.18 J/(g°C)
      
    • Heat of fusion = 333 J/g
      
    • Heat of vaporization = 2258 J/g
      
    1.   ?    22.4 kJ
    2.   ?    21.9 kJ
    3.   ?    37.3 kJ
    4.   ?    175 J
    5.   ?    18.0 J

16. The correct order for increasing boiling point among the noble gases is:
    
    

    1. He 2. Ne 3. Ar 4. Kr 5. Xe

    
    This phenomenon is best explained in terms of:
    1.   ?    hydrogen bonding
    2.   ?    dipole-dipole interaction
    3.   ?    covalent bonding
    4.   ?    Hund's rule
    5.   ?    London dispersion forces

17. 
    Chromium metal crystallizes as a body-centered cubic lattice. If the atomic radius of chromium is 125 pm, what is the volume of the unit cell?

    1.   ?    289 cm³
    2.   ?    2.41 x 10⁷ cm³
    3.   ?    2.41 x 10^-23 cm³
    4.   ?    4.41 x 10⁷ cm³
    5.   ?    4.41 x 10^-23 cm³

18. Chromium metal crystallizes as a body-centered cubic lattice. If the atomic radius of chromium is 125 pm what is the density of chromium metal?

    1.   ?    2.09 g/cm³
    2.   ?    7.18 g/cm³
    3.   ?    7.81 g/cm³
    4.   ?    2.76 g/cm³
    5.   ?    18.90 g/cm³

19. Aluminum crystallized in a face-centered cubic lattice. How many aluminum atoms can be found per unit cell in this structure?

    1.   ?    1
    2.   ?    2
    3.   ?    3
    4.   ?    4
    5.   ?    8

20. The triple point of CO₂ is 5.2 atm and -57°C. In a laboratory at EDHS, on a day when the pressure is 758 torr and the temperature in the room is 20°C, a solid sample of carbon dioxide will:

    1.   ?    freeze
    2.   ?    boil
    3.   ?    melt
    4.   ?    remain solid
    5.   ?    sublime