7. For each of the following pairs of substances, predict which member of the pair will have the higher melting point, and indicate why. a. NaCl and Cl2 b. NaF and MgO c. HCl and HF d. Ar and NO

58. Define the equilibrium vapor pressure of a substance. How and why does it depend on temperature? What occurs when a liquid boils? 59. What is Raoult's Law? Give an equation and define all terms, including units. When is it applicable and why? Illustrate your answer with a real example.

match the following    0.110 m CoI2      A. Highest boiling point     0.180 m NaCH3COO   B. Second highest boiling point     0.100 m CuI2   C. Third highest boiling point     0.390 m Sucrose (nonelectrolyte)   D. Lowest boiling point

Calcium sulfate (CaSO4) is insoluble in water. It is calculated that AH for solution is about zero. What is the sign of AS for the solution and why? 1. AS is positive. 2. AS is negative. Because 3. Mixing CaSO4 with water increases the number of possible arrangements. 4. Water molecules have fewer possible arrangements when Ca²+ and SO4²- ions are in solution due to being held tightly by strong ion-dipole interactions. 5. Water molecules exchange easily with those in the solvation shell. O2 and 3 O2 and 5 1 and 4 O2 and 4 0 1 and 3 O 1 and 5

For the table below, specify the dominant intermolecular force involved for each substance in the space immediately following the substance. Then in the last column, indicate which member of the pair you would expect to have the higher boiling point. Substance #1 Daninant Intermdecular Farce Substance #2 Dominant Intermedecular Fææ Substance with Higher Beling Pint a. HCl(g) b. CH;F CH;OH с. H20 H2S d. SIO2 SO, е. Fe Kr

28. Refer to the diagram below to determine a. the boiling point of ethanol when it is at normal atmospheric pressure. b. the boiling point of methanol at 96.0 kPa. Vapor Pressure (kPa) c. the atmospheric pressure at which diethyl ether boils at 20 °C. 120 110 100 90+ 80 70+ 60 5 55688 50- 30. 20 10. 0 0 atmospheric pressure (101 kPa) diethyl ether methanol 20 bp 34.6 ethanol bp 64.7 water 40 60 Temperature (°C) bp 78.2¹ bp 100 80 100

Arrange the following in terms of increasing boiling point using (<) less than equality.

28. Pure water boils at 100°C. What is the new boiling point of water after the addition of 13.12 g aluminum chloride, AIC13, to 615 g water?

Energy to sublime K(s) = 89.0 kJ/mol Electron affinity of F(g) = -328.0 kJ/mol First ionization energy of K(g) = 425.0 kJ/mol %3D Bond energy of F2(g) = 154.0 kJ/mol AHxn for K(s) + 1/2 F2(g) → KF(s) = -562.6 kJ/mol %3D 1st attempt O See Hint Determine the lattice energy of KF(s), using the data provided. kJ/mol

1. Adding 1 mol of NaCl to 1 kg of water lowers the vapor pressure of water more than adding 1 mol of C6H1206. Explain.