Aliphatic Carboxylic Acids
Organic compounds having carboxyl (—COOH) functional group with acidic property are carboxylic acids.
CH3COOH (acetic acid)
The term carboxyl is a composite word of the term 'carb' derived from carbonyl group (>C=O) and 'oxyl' derived from hydroxyl group (—OH) as:
>C=O(carbonyl)+-OH (hydroxyl)= -COOH (carboxyl)
Carboxylic acids are broadly classified as (i) Aliphatic carboxylic acids and (ii) Aromatic carboxylic acids, depending upon whether -COOH group is attached to alkyl (R-) chain and aromatic aryl (Ar-)group respectively.
The aliphatic carboxylic acid may be regarded as derivatives of alkanes in which one or more Hatoms have been substituted by –COOH group as shown as below:
Carboxylic acid The general formula of aliphatic saturated monocarboxylic acids (homologous series) is CnH2n+1COOH. (exception: Formic acid, HCOOH).
The carboxylic acids, aliphatic as well as aromatic, are further classified as mono-, di-, tri- or polycarboxylic acids according to the number of —COOH groups present in a molecule of carboxylic acid.
1.Aliphatic monocarboxylic acids: The carboxylic acids containing only one—COOH group per molecule are called monocarboxylic acids.
2 Aliphatic dicarboxylic acids: The carboxylic acids having two —COOH groups per molecule are called dicarboxylic acids.
3. Aliphatic tricarboxylic acids: The carboxylic acids having three —COOH groups per molecule
are called tricarboxylic acids.