The freezing point of benzene is 5.5°C. What is the freezing point of a solution of 8.30 g of naphthalene (C10H8) in 320. g of benzene (Kf of benzene = 4.90°C/m)?

Answer 1

mols naphthalene = grams/molar mass
m naphthalene = mols/kg solvent

Then delta T = Kf*m
Solve for delta T and subtract from the normal freezing point to find new freezing point.