Question 5: Colligative properties, such as boiling point elevation or freezing point depression, depend on the
number of dissolved particles in solution. (8 total pts, 4 pts each for 5a and 5b)
5a) At what temperature would a 1.55 m (molal) NaCl solution freeze, given a van't Hoff factor for NaCl is 1.9?
Use the Kf for water = 1.86°C/m.
5b) A 0.050 M solution of AlCl3 had an observed osmotic pressure of 3.85 atm at 20°C. Calculate the van't Hoff
factor AlCl3. Use for the gas constant (R=0.0821(L-atm)/(K-mol)).