Alkanoic AcidsAlkanoic Acids

• They look like alkanes but contain a carboxyl (COOH) group.

• Same names as alkanes but end in “oic”.

e.g. first alkanoic acid is METHANOIC ACID.

e.g. Full structural formula

HCOOH

Or

HCO2H

Shortened structural formula

Carboxyl functional group

Name of alkanoic acid

Molecular formula

Full structural formula

Shortened structural formula

Methanoic acid

HCOOH

Ethanoic acid

CH3COOH

Propanoic acid

C2H5COOH

Butanoic acid

C3H7COOH

HCOOH

CH3COOH

CH3CH2COOH

CH3CH2CH2COOH or

CH3(CH2)2COOH

Name of alkanoic acid

Molecular formula

Full structural formula

Shortened structural formula

Pentanoic acid

C4H9COOH

Hexanoic acid

C5H11COOH

Heptanoic acid

C6H13COOH

Octanoic acid

C7H15COOH

CH3-(CH2)3-COOH

CH3-(CH2)4-COOH

CH3-(CH2)5-COOH

CH3-(CH2)6-COOH

Naming Alkanoic AcidsNaming Alkanoic Acids

Rules1.Count the number of atoms in the

carbon chain to give the name of the parent alkanol.

2. Remove the –ol ending of the parent alkanol and replace it by –oic acid.