Question

Vitamin K is involved in normal blood clotting. When 1.36 g of vitamin K is dissolved in 25.0 g of camphor, the freezing point of the solution is lowered by 4.56 °C. The freezing point and Kf constant for camphor can be found here. Calculate the molar mass of vitamin K.

Answer 1

delta T = Kf*m.
Substitute and solve for molality.

Then m = mols/kg solvent.
Sustitute and solve for mols.

Then mol = grams/molar mass. You know mol and grams, solve for molar mass.

Answer 2

Thanks Dr. Bob,

Can you solve this step-by-step so that I can understand how to do this. I am really confused and lost. Thanks.