A 33.4 g sample of a nonelectrolyte was dissolved is 680. g of water. The solution's freezing point was -2.89°C. What is the molar mass of the compound?

Answer 1

delta T = Kf*molality
2.89 = 1.86*m
Solve for m.
Then m = mols/kg solvent. You know m and kg solvent, substitute and solve for mols.
Then mols = g/molar mass. You know mols and g, solve for molar mass.
Post your work if you get stuck.