General Chemistry II
Colligative Properties
1. If 5 grams of glycerol (mw = 92.09) is added to 300 g of water what is the new freezing and boiling point of the
solution? (Kf = 1.86 °C/m, Kb = 0.52 °C/m)
2. If 500 grams of sucrose (MW = 342.29 g/mol) is added to a solution of water and the final volume of the solution is
800 ml with a density of 0.9765 g/ml what the new freezing and boiling point of the solution? (K f = 1.86 °C/m, Kb = 0.52
°C/m)
3. if 50 grams of CaCl2 is added to 800 ml of water and a temperature of 25 °C. What is osmotic pressure (Π) of the
solution? (Π=iMRT, where i is the van’t hoff factor, M is molarity, R = 0.0821 L*atm/mol K and T is temperature in
kelvin)
4a. Calculate the new vapor pressure of a solution when 355 grams of sucrose (MW = 342.29 g/mol) is added to 300
ml of water at 40°C. (Density of water at 40°C is 1 g/cm3 and the vapor pressure of water at 40°C is 55.3 torr)
4b. Does the addition of sucrose make the solution more or less volatile?
4c. What is the new freezing and boiling point of the solution? (Kf = 1.86 °C/m, Kb = 0.52 °C/m)
5. When 1.0 gram of a compound is added to 500 ml water at 25°C the osmotic pressure of the solution is 1.69 atm
and produces 2 ions in solution. Determine the molar mass of the compound using Π=iMRT. What is the possible
identity of the compound if the cation is an alkali metal and the anion is a halogen?
6. How many grams of CO2 are present in a solution of 500 ml water if the partial pressure of the CO2 in solution is 3.2
atm? (The Henry’s Law constant for CO2 in water is 3.1*10-2 mol/Liter*atm)
7. What is the vapor pressure of a solution that contains 50 grams of pure toluene (vapor pressure 22 mmHg at 20°C)
and 60 grams of pure benzene (vapor pressure 75 mmHg at 20°C)?