A solution is prepared by dissolving 5.00 g of glycerin (C3H8O3) in 201 g of ethanol (C2H5OH). The freezing point of the solution is ________°C. The freezing point of pure ethanol is -114.6°C at 1 atm. The molal-freezing-point-depression constant (Kf) for ethanol is 1.99°C/m. The molar masses of glycerin and of ethanol are 92.1 g/mol and 46.1 g/mol, respectively.
delta T = i*Kf*molality
i = 1
Kf = 1.99
molality = moles glycerin/kg solvent
mols glycerin = 5/molar mass glycerin = ?
kg solvent = 0.201 kg
Solve for delta T and subtract from -114.6
Post your work if you get stuck.