Freezing Point Depression Calculator

About this calculator

This calculator finds freezing point depression using the colligative property formula ΔTf = i·Kf·m, where i is the van't Hoff factor (number of particles the solute dissociates into), Kf is the solvent's cryoscopic (molal freezing point depression) constant, and m is the solution's molality. Subtracting ΔTf from the pure solvent's freezing point gives the solution's actual freezing point.

Chemistry students use it in lab to determine an unknown solute's molar mass from measured freezing point depression, and it explains real-world uses like why salt lowers the freezing point of icy roads and why antifreeze (ethylene glycol) protects a car's radiator. Enter the molality, Kf, and van't Hoff factor to get ΔTf and the new freezing point.