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_vHeat Energy (kJ)
heat_kj = mass * latent_heat_v / 1000Variables
| Variable | Description | Default |
|---|---|---|
mass | Mass(kg) | 1 |
latent_heat_v | Latent 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.
- 01Q = m * Lv
- 02Q = 1 * 2260000
- 03Q = 2,260,000 J = 2260 kJ
Frequently Asked Questions
Why is the heat of vaporization so much larger than fusion?
Vaporization requires completely separating molecules from each other against all intermolecular forces, while melting only loosens the crystal structure.
Why does sweating cool you down?
Evaporating sweat absorbs a large amount of heat from your skin (the latent heat of vaporization), effectively cooling the body.
Does boiling point depend on pressure?
Yes. Lower pressure lowers the boiling point. This is why water boils at a lower temperature at high altitudes.
Ready to run the numbers?
Open Heat of Vaporization Calculator