How are esters formed?

Esters are formed through a reaction known as esterification, which specifically occurs by the condensation of an alcohol and a carboxylic acid. In this process, the hydroxyl group (-OH) from the carboxylic acid and a hydrogen atom from the alcohol combine to release water (H₂O). The remaining parts of the molecules then bond together to create the ester. This reaction is characterized by the loss of the equivalent of one water molecule, thus it is referred to as a condensation reaction.

The structure of the resulting ester typically consists of an alkyl group attached to the carbonyl carbon of the acid, establishing a distinct ester functional group. These compounds are commonly used in flavors, fragrances, and as solvents due to their pleasant smells and volatility. The specific conditions and catalysts can vary, but the essential reaction between an alcohol and a carboxylic acid remains the same in the formation of esters.