A solution which contains 40.3 g of an unknown molecular compound in 360 g of water freezes at -5.07°C.

What is the molar mass of the unknown?

1 answer

delta T = Kf*m
Substitute and solve for molality.

molality = mols/kg solvent.
Substitute and solve for mols.

mols = grams/molar mass. You know grams and mols, solve for molar mass.