Carbon compounds containing a carboxyl function group, -COOH are called
carboxylic acids. The Carboxyl group is the combination of carbonyl group and the hydroxyl group (-OH).
However, carboxyl group has its own characteristic reaction. Carboxylic
acids may be aliphatic (R – COOH) or aromatic (Ar – COOH) depending on the
alkyl or aryl group attached to carboxylic carbon. Some higher members of
aliphatic carboxylic acids (C12 to C18) known as fatty
acids occur in natural fats as esters of glycerol.