Freezing Point Depression Calculator

Find how much a solute lowers the freezing point.

Freezing point decrease (°C) 3.72

Formula: ΔTf = i · Kf · molality

Step-by-step with your numbers:

1. Values used:

2. Van't Hoff factor (i) = 2

3. Cryoscopic constant (Kf) = 1.86 °C/m

4. Molality = 1 mol/kg

6. Freezing point decrease = Van't Hoff factor (i) x Cryoscopic constant (Kf) = 2 x 1.86 = 3.72°C

Did we solve your problem today?

Dissolved solutes lower a solvent's freezing point (why salt melts ice).

The math behind it

ΔTf = i × Kf × molality. Water's Kf = 1.86 °C/m.

NaCl (i=2), 1 m → −3.72 °C.

Road salt?

It dissolves into ions, depressing ice's melting point.