The boiling point of diethyl ether CH3CH2OCH2CH3 is 34.500C at 1 atmosphere. A nonvolatile, nonelectrolyte that dissolves in diethyl ether is cholesterol .

Question

How many grams of cholesterol, C27H46O (386.6 g/mol), must be dissolved in 263.0 grams of diethyl ether to raise the boiling point by 0.4500C ?

Answer 1

delta T = Kb*molality. You know delta T and Kb (somewhere in the problem or you have a table containing the information), solve for molality.
Then molality = moles/kg solvent, you know m and kg solvent, calculate moles.
Then moles = grams/molar mass, calculate grams.
and molality = moles/kg solvent.