In an esterification reaction, a carboxylic acid reacts with an alcohol to form an ester and water.

Carboxylic acid + Alcohol  ↔  Ester + Water

Esters consist of two hydrocarbon chains, as labelled R-COOH (for the carboxyl group) and R'-OH (for the hydroxyl group) in this simulation. Esters are natural organic compounds with broad applications in biology (Phosphodiester bounds, fruit flavor), chemistry, industry (soaps, artificial flavors and aromas).

An ester's name is based on the name for the acid followed by the suffix -oate.

For example:

• Ethanoic acid reacts with methanol to form methyl ethanoate and water.
• Propanoic acid reacts with ethanol to form ethyl propanate and water.