A series of compounds in which the same functional group substitutes for hydrogen in a carbon chain is called ________.

A homologous series is a group of compounds in which the same functional group substitutes for hydrogen in a carbon chain. A homologous series of organic compounds has the same functional group and shows similar chemical properties but differs by a CH2 unit in their molecular formula. This group of compounds shows slow changes in physical properties like boiling point and melting point.