Answer to Question #139814 in General Chemistry for Harvey Jed A. Iman

Question

Calculate the freezing point depression of the given electrolytic solution: 5.7 g CaCl2 (calcium chloride) in 18.6 kg H2O (water)

Answer 1

$$\Delta T = iKC_m$$

$$C_m = {n(CaCl_2) \over m(H_2O)} = {m(CaCl_2) \over M(CaCl_2)*m(H_2O)}$$

$$\Delta T= 3*1.86*{5.7 \over 111*18.6} = 0.015$$

$$T_{freezing} = 0^oC-0.015^oC = -0.015^oC$$