Heat of Vaporization Calculator Formula

Understand the math behind the heat of vaporization calculator. Each variable explained with a worked example.

Formulas Used

Heat Energy Required

heat = mass * latent_heat_v

Heat Energy (kJ)

heat_kj = mass * latent_heat_v / 1000

Variables

VariableDescriptionDefault
massMass(kg)1
latent_heat_vLatent Heat of Vaporization(J/kg)2260000

How It Works

Heat of Vaporization

The heat of vaporization is the energy needed to convert a liquid to gas at constant temperature.

Formula

Q = m * L_v

For water, L_v = 2,260,000 J/kg = 2260 kJ/kg, much larger than the heat of fusion because more energy is needed to fully separate molecules.

Worked Example

Boiling 1 kg of water at 100°C.

mass = 1latent_heat_v = 2260000
  1. 01Q = m * Lv
  2. 02Q = 1 * 2260000
  3. 03Q = 2,260,000 J = 2260 kJ

Ready to run the numbers?

Open Heat of Vaporization Calculator