Heat of Vaporization
| Formula / Notation | ΔH_vap = −ΔH_cond |
|---|---|
| Also Known As | Enthalpy of vaporization, latent heat of vaporization, heat of evaporation, molar heat of vaporization |
What is Heat of Vaporization?
The heat of vaporization (enthalpy of vaporization, latent heat of vaporization) is the amount of energy required to convert a unit mass of a liquid into vapor at constant temperature and pressure. It represents the energy needed to overcome intermolecular attractive forces. Water has an exceptionally high heat of vaporization (2260 J/g) due to hydrogen bonding.
Formula & Notation
Other Names / Synonyms: Enthalpy of vaporization, latent heat of vaporization, heat of evaporation, molar heat of vaporization
Properties & Characteristics
Uses & Applications
Safety Information
Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.
Key Facts
Frequently Asked Questions
The heat of vaporization (enthalpy of vaporization, latent heat of vaporization) is the amount of energy required to convert a unit mass of a liquid into vapor at constant temperature and pressure. It represents the energy needed to overcome intermolecular attractive forces. Water has an exceptionally high heat of vaporization (2260 J/g) due to hydrogen bonding.
Cooling by evaporation (sweating, evaporative coolers). Steam power generation (water vaporization). Refrigeration and air conditioning (refrigerant vaporization). Distillation and evaporation processes. Weather and climate (clouds, humidity). Calculating vapor pressures at different temperatures.
Large amounts of energy required — industrial steam generation safety. Evaporation of flammable solvents creates fire and explosion hazards. Volatile toxic solvents — inhalation hazard during evaporation. Proper ventilation essential when evaporating chemicals.
The formula or notation for Heat of Vaporization is: ΔH_vap = −ΔH_cond