Boiling & Freezing Point Calculator

The liquid the solute is dissolved in. Each preset supplies its own boiling and freezing constants (Kb, Kf) and normal boiling/freezing points.

Pick Custom to type these four values yourself in the fields below.

The boiling-point elevation constant of the solvent, used only in custom mode.

Water's Kb is 0.512 °C·kg/mol.

The freezing-point depression constant of the solvent, used only in custom mode.

Water's Kf is 1.86 °C·kg/mol.

The pure solvent's boiling point at 1 atm, used in custom mode as the baseline the rise is added to.

Water boils at 100 °C.

The pure solvent's freezing point, used in custom mode as the baseline the drop is subtracted from.

Water freezes at 0 °C.

Moles of dissolved solute per kilogram of solvent. The shifts scale directly with it.

Molality (per kg) is used instead of molarity so the value does not drift with temperature.

How many particles each dissolved unit splits into — what actually drives the effect.

• 1: sugar and other non-ionic solutes.
• 2: NaCl (Na⁺ + Cl⁻).
• 3: CaCl₂ (Ca²⁺ + 2 Cl⁻).