Freezing Point Depression Calculator
🧪 Solutions & Molarity. Use the Freezing point depression formula to find drop δt_f, van 't hoff factor i, k_f, molality: pick the value you want, type the others, and the answer updates as you go.
Water: K_f = 1.86 °C·kg/mol.
Pick the ○ next to the value you want to find, fill in the others, and it solves as you type.
What each letter means
| Quantity | Unit |
|---|---|
| Drop ΔT_f | °C |
| van 't Hoff factor i | no unit |
| K_f | °C·kg/mol |
| Molality | mol/kg |
Worked example
Find the drop δt_f when van 't Hoff factor i = 2, K_f = 1.86 °C·kg/mol, Molality = 1 mol/kg.
Using Δ Tf = i Kf m: Drop ΔT_f = 3.72 °C.
Frequently asked questions
What is the formula for Freezing point depression?
Δ Tf = i Kf m. Water: K_f = 1.86 °C·kg/mol.
What do the letters stand for, and what units are used?
Drop ΔT_f in °C, van 't Hoff factor i, K_f in °C·kg/mol, Molality in mol/kg.
How do you calculate drop δt_f?
Put the values into Δ Tf = i Kf m. For example, with van 't Hoff factor i = 2, K_f = 1.86 °C·kg/mol, Molality = 1 mol/kg, drop δt_f = 3.72 °C.
Can I solve for a different value?
Yes. In the calculator above, pick the circle next to any value (drop δt_f, van 't hoff factor i, k_f, molality) and fill in the others: it rearranges the formula for you.
