This document discusses the calculation of freezing point depression for a solution. It shows that the freezing point depression equals 1.88 times the molality times the freezing point constant of 1.86, which for a 0.5 molal solution equals 1.75°C. It then states that the freezing point of the solution is equal to the freezing point of water minus the freezing point depression, which for this solution is -1.75°C.