Assignment

1. A solution of urea in water has a boiling point of 100.130 °C. Calculate the freezing point of the same solution.
   Given: K_f = -1.858 °C, K_b = 0.512 °C.
2. A certain solution of benzoic acid in benzene freezes at 3.1 °C. What information about the number of particles and the structure of benzoic acid at the temperature can be deduced?
   The freezing point of pure benzene is 5.5 °C, and the cryoscopic constant K_f = -4.90 K·kg·mol^-1.
3. Determine the molecular weight of non-volatile solute (Camphor) by the cryoscopic method using Carbon tetrachloride as the solvent.
   Given: K_f = -29.8 °C·kg·mol^-1, i = 1, W_A = 15 g, W_B = 5 g.
4. Determine the freezing point depression constant K_f of the solvent Carbon disulfide using Sulfur as the solute.
   Given: W_A = 10 g, W_B = 2 g, M_B of Sulfur = 256.52 g/mol.
5. A solution of sucrose (molecular weight = 342) is prepared by dissolving 34.2 g of it in 1000 g of water. Sucrose has a van ’t Hoff factor i = 1. Find the freezing point of the solution in Kelvin.
   Given: K_f for water = -1.86 K·kg·mol^-1.