1. Consider a series of chloride salts, MCl 2. As the charge-to- radius ratio of M 2+ a, the hydration energy of M 2+ b in magnitude and the crystal lattice energy of MCl 2 c in magnitude. a / b / c 1234567891011121314151617181920 2122232425262728293031323334353637383940 41424344454647484950 1.increases / decreases / increases 2.increases / increases / increases 3.increases / increases / decreases 4.increases / decreases / decreases 5.increases / does not change / may increase or decrease

2. Which of the following metal ions has the most negative heat of hydration? 1234567891011121314151617181920 2122232425262728293031323334353637383940 41424344454647484950 1.Ca 2+ 2.K + 3.Mn 2+ 4.Li + 5.Al 3+

3. To calculate the molality of a solution, which of the following must be measured? I. mass of solute II. mass of solvent III. total volume of solution 1234567891011121314151617181920 2122232425262728293031323334353637383940 41424344454647484950 1.I and II 2.I and III 3.II and III 4.only I 5.I, II and III

4. Calculate the molality of a solution prepared by dissolving 150. grams of sodium dichromate dihydrate, Na 2 Cr 2 O 7 · 2H 2 O in 350. gm of water. 1234567891011121314151617181920 2122232425262728293031323334353637383940 41424344454647484950 1.1.44 m 2.1.56 m 3.1.79 m 4.1.86 m 5.2.30 m

5. Calculate the mole fraction of C 2 H 5 OH in a solution that contains 46 grams of ethyl alcohol, C 2 H 5 OH, and 64 grams of methyl alcohol, CH 3 OH. 1234567891011121314151617181920 2122232425262728293031323334353637383940 41424344454647484950 1.0.33 2.0.42 3.0.50 4.0.67 5.1.5

6. At 25°C a solution consists of 0.450 mole of pentane, C 5 H 12, and 0.250 mole of cyclopentane, C 5 H 10. What is the mole fraction of pentane in the vapor that is in equilibrium with this solution? The vapor pressure of the pure liquids at 25°C are 451 torr for pentane and 321 torr for cyclopentane. Assume that the solution is an ideal solution. 1234567891011121314151617181920 2122232425262728293031323334353637383940 41424344454647484950 1.0.284 2.0.551 3.0.716 4.0.643 5.0.357

7. The freezing point of a solution made by dissolving 0.200 g of a molecular compound in 100. g of H 2 O is - 0.0120°C. Calculate the molecular weight of the compound. The compound does not ionize in water. K f for H 2 O = 1.86°C/m. 1234567891011121314151617181920 2122232425262728293031323334353637383940 41424344454647484950 1.155 amu 2.215 amu 3.310 amu 4.395 amu 5.450 amu

8. When 27.0 g of an unknown nonelectrolyte is dissolved in 250.0 mL of benzene, the solution boils at 82.5°C. Calculate the molecular weight of the unknown nonelectrolyte. The K b for benzene = 2.53°C/m. The boiling point of pure benzene is 80.1°C. The density of benzene = 0.876 g/mL. 1234567891011121314151617181920 2122232425262728293031323334353637383940 41424344454647484950 1.60 g/mol 2.130 g/mol 3.220 g/mol 4.110 g/mol 5.150 g/mol

9. A 0.0100 m solution of HX, a weak acid, freezes at - 0.02000°C. Calculate the % ionization of HX. K f for water = 1.86°C/m. 1234567891011121314151617181920 2122232425262728293031323334353637383940 41424344454647484950 1.2.3% 2.7.5% 3.9.5% 4.11% 5.18%

10. 1234567891011121314151617181920 2122232425262728293031323334353637383940 41424344454647484950 1.62% 2.64% 3.66% 4.68% 5.83%

11. Which of the following is not an advantage of osmotic pressure over boiling point elevation and freezing point depression for the determination of molecular weights? 1234567891011121314151617181920 2122232425262728293031323334353637383940 41424344454647484950 1.The relatively large change in osmotic pressure is easier to measure accurately than the small boiling point elevation. 2.The relatively large change in osmotic pressure can be determined without the special apparatus needed for accurate measurement of the smaller freezing point depression. 3.A more dilute solution can be used for osmotic pressure measurements thereby saving money when the molecular weights of expensive substances are to be determined. 4.Use of a more dilute solution allows determinations for sparingly soluble high- molecular-weight substances. 5.Osmotic pressure can be used to accurately determine the molecular weight of impure substances.