The difference between using freezing-point depression to find the molar mass of an electrolyte and using the same method to find the molar mass of a nonelectrolyte is that when dealing with an electrolyte, the student also must know

the van't Hoff factor for the known solvent
the van't Hoff factor for the unknown electrolyte
the van't Hoff factor for the nonelectrolyte
the molarity of the pure electrolyte
There is no difference between an electrolyte and a nonelectrolyte in this calculation