1. Arrange the following substances in the expected order of increasing boiling pt and give the types of intermolecular forces in each. H₂O, NH₃, CH₄, CH₃CH₃. (5pts)
2. Using figure 10.10 from your book, calculate the entropy change of vaporization of water. (15pts)

1. At 25 °C and 2.00 atm, the solubility of CO₂(g) in water is 0.0678 M. When air at 1 atm and 25 °C is in equilibrium with water, Use Henry’s law to get the concentration of dissolved CO₂? The partial pressure of CO₂ in air is approximately 4.0 x 10^-4 atm. (10pts)
2. The vapor pressure of benzene (C₆H₆) at 25°C is 95.1 mm Hg. What is the vapor pressure of benzene above a solution in which 5.05 g of benzoic acid, C₆H₅COOH, is dissolved in 245 g C₆H₆? Use Raoult’s law. (10pts)
3. Draw a picture showing hydrogen bonding between several molecules of water (2D is ok here) (2pts)
4. What is the normal boiling pt in °C of ethanol if a solution prepared by dissolving 13.0 g NaCl in 285 g of ethyl alcohol has a boiling pt of 79.1 °C? Assume complete dissociation of NaCl. The K­_b for ethanol is 1.22 (°C kg)/mol. (10pts)
5. The experimental dipole moment of BrCl is 0.518 D and the distance between atoms is 213.9 pm. What is the percent ionic character of the BrCl bond? (μ = Q x r) 1D = 3.336 x 10^-30 Cm (5pts)
6. Ethyl alcohol, CH₃CH₂OH is miscible with water but 1-heptanol CH₃CH₂CH₂CH₂CH₂CH₂CH₂OH is only slightly miscible in water. Explain. (3pts)
7. Give the name of the packing, the name of the unit cell, and the number of atoms in the unit cell for each of the following packing structures/unit cell diagrams. (9 pts)

(a)

(b)

(c)

1. Oxygen has a triple point at 54.3 K and 1.14 mm Hg and a critical point at 154.6 K and 49.77 atm. The density of the liquid is 1.14 g/cm3 and the density of the solid is 1.33 g/cm3. Sketch a phase diagram labeling all points of interest (not to scale). (10pts)

Pressure (atm)

Temperature (K)

1. At 500 K, the vapor pressure of Hg is 39.3 mm Hg. Use the Clausius-Clapeyron equation to find the temperature at which the vapor pressure of mercury is 114.4 mm Hg. ΔH_vap = 59.229 kJ/mol for Hg (10pts)
2. Express the following aqueous concentrations in the unit indicated: (6pts)
   1. 0.0025 g KI/L water as ppm of KI
   2. 0.0035% NaCl by mass as ppb NaCl
   3. 2.40 ppm F^–, as molarity of fluoride ion.
3. How many mL of ethanol, CH₃CH₂OH (d = 0.789 g/mL), must be mixed with 125 mL of benzene, C₆H₆ (d = 0.879 g/mL) in order to produce a solution that is 0.0654 m ethanol? (15 pts)