Question

Pure benzene has a normal freezing point of 5.50 degrees Celsius. A solution containing 11.4 grams of a molecular substance dissolved in 150.0 grams of benzene (Kf=5.12C/m) has a freezing point of 1.20 degrees Celsius. What is the molar mass of the solute?
delta T = Kf*molality.
Solve for molality and substitute in the next equation.

molality = moles/kg solvent. Solve for moles and substitute in the next equation.

moles = grams/molar mass. Solve for molar mass.

Related Questions

3.92g of a nondissociating compound are dissolved in 400.g of liquid benzene. The freezing point of... What is the freezing point of a solution of 1.17g of 1-naphthol, C10H8O, dissolved in 2.00ml of benz... 1) Benzene freezes at 5.45 degrees celsius. The Kf for benzene is -5.07C/m. What would be the freezi... A 1.065-g sample of an unknown substance is dissolved in 30.00 g of benzene; the freezing point of t...