Functional Groups & Homologous Series

Functional Group: An atom or group of atoms in a molecule that determines its characteristic chemical properties (e.g., $$\text{--OH}$$, $$\text{--CHO}$$, $$\text{--COOH}$$).

Homologous Series: A family of organic compounds having the same functional group, similar chemical properties, and conforming to a general molecular formula.

Characteristics: Successive members differ by a $$\text{--CH}_2\text{--}$$ unit and a molecular mass of $$14\text{ u}$$.