Evaporation — Definition, Formula, Properties & Uses | AllChemicals | AllChemicals

Q: What is the formula for Evaporation?

The formula or notation for Evaporation is: Evaporation rate ∝ vapour pressure × surface area × T

Formula / Notation	Evaporation rate ∝ vapour pressure × surface area × T
Also Known As	Vaporisation (surface), volatilisation, solvent evaporation

What is Evaporation?

The conversion of a liquid to vapor at temperatures below the boiling point at the surface of the liquid. It is an endothermic process where higher-energy molecules escape from the liquid surface. Evaporation causes cooling because it removes the most energetic molecules.

Formula & Notation

Evaporation rate ∝ vapour pressure × surface area × T

Other Names / Synonyms: Vaporisation (surface), volatilisation, solvent evaporation

Properties & Characteristics

Evaporation is the phase transition of molecules from the liquid surface to the vapour phase at temperatures below the boiling point. Unlike boiling, evaporation occurs only at the surface. The rate depends on temperature, surface area, vapour pressure of the liquid, and air flow across the surface. The enthalpy of vaporisation must be supplied, cooling the remaining liquid (evaporative cooling). At equilibrium with vapour, the dynamic process continues with equal condensation rate.

Uses & Applications

Evaporation is exploited in: solvent removal from solutions (rotary evaporation), cooling by perspiration, industrial drying (spray drying, fluidised bed drying), salt production (solar evaporation ponds), and natural water cycle dynamics.

Safety Information

Evaporation of volatile flammable solvents (diethyl ether, pentane, acetone) can produce explosive vapour-air mixtures. Volatile toxic substances (mercury, benzene, formaldehyde) create inhalation hazards through evaporation. Always work with volatile chemicals in a fume hood.

Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.

Key Facts

Term Evaporation

Formula Evaporation rate ∝ vapour pressure × surface area × T

Index All "E" terms

Synonyms Vaporisation (surface), volatilisation, solvent evaporation

Frequently Asked Questions

What is Evaporation?

The conversion of a liquid to vapor at temperatures below the boiling point at the surface of the liquid. It is an endothermic process where higher-energy molecules escape from the liquid surface. Evaporation causes cooling because it removes the most energetic molecules.

What is Evaporation used for?

Is Evaporation hazardous?

What is the formula for Evaporation?

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