General Chemistry II Problems
COLLIGATIVE PROPERTIES
1. Calculate the vapor pressure when 10.o mL glycerol (C3H8O3) is added to 500.0 mL water at 500C. At this temperature the vapor pressure of pure water is 92.5 torr and its density is 0.988 g/mL. Density of glycerol is 1.26 g/mL.
2. Calculate the boiling point and freezing point of the solution if 1.00 kg of ethylene glycol (C2H6O2) is added to a car radiator which contains 4450 g water.
a. Kb of water = 0.512 oC/m at normal boiling point of 100oC
b. Kf of water = 1.86 oC/m at normal freezing point of 0Oc
3. A 0.30 M solution of sucrose at 370C has approximately the same osmotic pressure as blood. What is the osmotic pressure of the blood?
4. Barbiturates are synthetic drugs used as sedatives and hypnotics. Barbital ( = 184.2 g/mol) is one of the simplest of these drugs. What is the boiling point of a solution prepared by dissolving 42.5 g of barbital in 825 g of acetic acid?
Kb = 3.07°C/m, boiling point of pure acetic acid = 117.9°C
5. When 0.55 g pure benzoic acid (C7H6O2) is dissolved in 32.0 g of benzene, the freezing point of the solution is 0.36C lower than the freezing point value of 5.5C for the pure solvent. (a) Calculate the molecular weight of benzoic acid in benzene. (b) Use the structure of the solute to account for the observed value:
6. Biochemists have discovered more than 400 mutant varieties of hemoglobin (Hb), the blood protein that carries oxygen throughout the body. A physician studying a form of Hb associated with a fatal disease first finds its molar mass (M). She dissolves 21.5 mg of the protein in water at 5.0 oC to make 1.50mL of solution and measures an osmotic pressure of 3.61 torr. What is the molar mass of this Hb mutant?
7. The boiling point of a solution containing 5.55 g of an unknown nonvolatile substance dissolved in 15.0 g of water is 103.3 oC. Calculate the molar mass of the compound.
8. Calculate the freezing point of a 500.0 mL sample of aluminum sulfate solution
1. Calculate the vapor pressure when 10.o mL glycerol (C3H8O3) is added to 500.0 mL water at 500C. At this temperature the vapor pressure of pure water is 92.5 torr and its density is 0.988 g/mL. Density of glycerol is 1.26 g/mL.
2. Calculate the boiling point and freezing point of the solution if 1.00 kg of ethylene glycol (C2H6O2) is added to a car radiator which contains 4450 g water.
a. Kb of water = 0.512 oC/m at normal boiling point of 100oC
b. Kf of water = 1.86 oC/m at normal freezing point of 0Oc
3. A 0.30 M solution of sucrose at 370C has approximately the same osmotic pressure as blood. What is the osmotic pressure of the blood?
4. Barbiturates are synthetic drugs used as sedatives and hypnotics. Barbital ( = 184.2 g/mol) is one of the simplest of these drugs. What is the boiling point of a solution prepared by dissolving 42.5 g of barbital in 825 g of acetic acid?
Kb = 3.07°C/m, boiling point of pure acetic acid = 117.9°C
5. When 0.55 g pure benzoic acid (C7H6O2) is dissolved in 32.0 g of benzene, the freezing point of the solution is 0.36C lower than the freezing point value of 5.5C for the pure solvent. (a) Calculate the molecular weight of benzoic acid in benzene. (b) Use the structure of the solute to account for the observed value:
6. Biochemists have discovered more than 400 mutant varieties of hemoglobin (Hb), the blood protein that carries oxygen throughout the body. A physician studying a form of Hb associated with a fatal disease first finds its molar mass (M). She dissolves 21.5 mg of the protein in water at 5.0 oC to make 1.50mL of solution and measures an osmotic pressure of 3.61 torr. What is the molar mass of this Hb mutant?
7. The boiling point of a solution containing 5.55 g of an unknown nonvolatile substance dissolved in 15.0 g of water is 103.3 oC. Calculate the molar mass of the compound.
8. Calculate the freezing point of a 500.0 mL sample of aluminum sulfate solution