Pure lauric acid is melted and the freezing point is determined to be 43 degrees celsius.

Question

A solution is made by dissolving .50 grams of paradicholrobenzene into 3.00 grams of lauric acid.
Determine the molality of this solution. I got 1.1m. which is right.

But then it says the freezing point of the mixture is measured and found to be 39 degrees celsius. Then it says... determine the freezing poitn constant (kf) for lauric acid. how do i do that?

Answer 1

delta T = Kf*m
You know delta T (43-39) and you know m. Calculate Kf.