Question

The melting point of a pure solvent is -116.3 C. If 352 g of an ionic solid is added to 567.7g of the solvent, the new melting point is -121.6 C. What is the molar mass of the ionic solute?

Answer 1

delta T = i•Kf•molality

Molality = moles / kg solvent

You have molality and kg solvent, solve for moles.

Moles = grams / molar mass. You have moles and grams, solve for molar mass.