Molecular Weight by Freezing Point Depression

Learning Objectives:

Students use freezing point depression, which occurs when the freezing point of a compound decreases upon adding it to a solution, to determine molecular weight.


Students measure the freezing point depression of an aqueous solution of the unknown by measuring the freezing points of both the pure solvent and the solution. The difference between these points is the freezing point depression, which can be used to calculate the molality of the solution.