The carboxyl group, consists of a carbonyl group
attached to a hydroxyl group, hence its name carboxyl Carboxylic acids
may be aliphatic (RCOOH) or aromatic (ArCOOH) depending on the group,
alkyl or aryl, attached to carboxylic carbon Large  number of carboxylic
acids are found in nature Some higher members of aliphatic carboxylic
acids (C12 – C18) known as fatty acids, occur in natural fats as esters of
glycerol