Question

Correct order of freezing point of given solution ? 1) 0.1 M glucose 2) 0.2 M urea 3) 0.1 M NaCl 4) 0.05 M `CaCl_2`

Answer 1

For the purposes of this question: `(1) < (4) < (2) = (3)`.

Explanation:

This question is mainly asking about the van't Hoff factor. This is the number of molecules, that on average result upon solvation of compound in solution. Let's assume you're referring to molality as well to make this easier on me because you aren't giving me enough data to calculate it.

`T_f = iK_f*m`

(a) `T_f = 1 * 0.1m * K_f = 0.1K_f`
(b) `T_f = 1 * 0.2m * K_f = 0.2K_f`
(c) `T_f = 2 * 0.1m * K_f = 0.2K_f`
(d) `T_f = 3 * 0.05m * K_f = 0.15K_f`

At a higher level of detail these would be different, and sodium chloride would have less of an effect on freezing point.