A solution is prepared with an unknown compound with an empirical formula of C3H7NO.

The solution is made by dissolving 30.0 mg of compound in 1.200 g of the organic solvent biphenyl. The freezing point was depressed by 1.37C. What are the molar mass and molecular formula of the compound?

1 answer

delta T = Kf*molality
Solve for molality.

molality = moles/kg solvent
Solve for moles

moles = grams/molar mass
Solve for molar mass.

molar mass/empirical mass and round to the nearest whole number = n
molecular formula is (empirical formula)n