2. When 0.354 g of an unknown nonelectrolyte compound was dissolved in 12.5 g of benzene a solution was formed that froze at 4.46°C.

(a) Calculate the molar mass of the unknown compound. The freezing point of benzene is 5.48°C, and the Kf of benzene is 5.12 °C/Molal. Show your work

1 answer

delta T = kf*m
Substitute and solve for m

m = mols/kg solvent
Substitute and solve for m

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