When 2.50g of an unknown solute is dissolved in 40.0g of ethanol the solution boils at 79.4C. The normal boiling point of this substance is 78.4C and it has a kb of 1.22C/m.

Question

When 2.50g of an unknown solute is dissolved in 40.0g of ethanol the solution boils at 79.4C. The normal boiling point of this substance is 78.4C and it has a kb of 1.22C/m.
(a) What is the molality of this solution?
(b) What is the molecular weight of the solute?

DrBob222 · Answer

delta T = Kb*m Solve for m molality = grams/molar mass solve for molar mass.