Homologous Series and Functional Groups

Core concept

For example, the alcohol homologous series (methanol, ethanol, propanol...) all share the -OH functional group, giving them similar chemical reactions despite differing chain lengths. Other common functional groups include the carboxylic acid group (-COOH, found in vinegar/acetic acid) and the aldehyde group (-CHO). Because members of a homologous series share a functional group, they undergo similar types of chemical reactions, though the specific rate or vigour of the reaction may vary with molecular size.