Organic Chemistry - Chemistry and the Chemical Industry - page 49

FUNCTIONAL GROUPS

Hydroxyl (alcohol) − OH

O

Carbonyl (ketone, aldehyde)

C

O

Carboxyl (acid)
Nitrile (cyano)

C OH

− CN

Alkoxyl (ether) − O − R (R is an alkyl group)

Halide (chloride, bromide, iodide) − Cl, − Br, − I

Amino − NH 2

Nitro − NO 2

Other atoms or groups of atoms such as oxygen, nitrogen, and chlorine may
be substituted for hydrogen in an aliphatic hydrocarbon. If a hydrogen in
ethane is substituted with the hydroxyl group ( OH), it becomes ethyl

alcohol. If the hydrogen is replaced by chlorine, the compound is ethyl
chloride. Likewise, by replacing a hydrogen with an amino group (

−

NH 2 ),
ethyl amine is formed. These groups substituted for a hydrogen are called
functional groups because they determine most of the chemical properties
(functions) of organic compounds.

−