Solutions Worksheet
1. Determine the mass percent, mole fraction, and molality of a H2SO4 solution composed
of 73.4 g H2SO4 dissolved in 972 g of water.
2. A solution is made by combining 66.0 grams of acetone (C3H6O) and 146.0 grams of
water. Calculate the mass percent, mole fraction, and molality of this solution.
3. Determine the boiling point and the freezing point of a solution made by dissolving 25.0
grams of trichlormethane, CHCl3 (molar mass = 119.4 g/mol) in 75.0 grams of benzene.
4. Determine the boiling point and freezing point of a solution made by dissolving 25.0
grams CaCl2 (molar mass = 110.98 g/mol) in 150. grams of water.
5. A solution is made by dissolving 0.650 grams of a molecular substance in 27.8 grams of
the solvent diphenyl results lowers the freezing point of diphenyl by 1.560C. The Kf for
diphenyl is 8.00 0C/m. Calculate the molar mass of the dissolved substance.
6. I almost forgot vapor pressure! Determine the vapor pressure of each of the following
solutions:
a. 125 grams of glucose (molar mass = 180. g/mol) in 125 grams of water at 250 C.
The vapor pressure of pure water at this temperature is 23.76 mmHg.
b. 75.0 grams CaCl2 (molar mass = 110.98 g/mol) in 225 grams of water at 250 C.
The vapor pressure of pure water at this temperature is 23.76 mmHg.
7. When 1.50 grams of the protein is dissolved in 0.250 L of solution at 277 K the resulting
solution has an osmotic pressure of 2.60 mmHg. What is the molar mass of this protein?
Assume the protein is a nonelectrolyte.
8. Let’s pick an amount of heat, say, 755 J. If you add this heat to a 100.0 g sample of
benzene, it could melt (if the sample was a solid at its melting point), warm up (if it was a
liquid), or boil (if it was at its boiling point). If you added 755 J to a 100.0 g sample of
water, it would melt, warm up, or boil less. For each solvent, how much would it melt,
warm up, or boil??
Formula
Melting point (oC)
Boiling point (oC)
Boiling point constant (oC/m)
Melting point constant (oC/m)
Formula Mass (g/mol)
Heat of fusion (J/g)
Heat of vaporization (J/g)
Specific heat (J/goC)
Water
Benzene
H2O
0.00
100.00
.512
1.86
18.02
334
2250
4.18
C6H6
5.5
80.1
2.53
5.12
78.1
126
394
1.51