Question

An aqueous solution of potassium sulfate (K2SO4) has a freezing point of –2.24 oC. What is its molality? (Kf = 1.86 oC•m–1)

Answer 1

For the answer to the question above,
in this problem we can use the concept of freezing point depression since we are given the freezing point of the solution.

ΔT = -k(f) x m x i
-2.24 - 0 = -1.86 x m x 3
m = 0.4014
So the answer to your question is m = 0.4014