Carboxylic acid Carboxylic acid A carboxylic acid is an organic compound that contains a carboxyl group (C(=O)OH). The general formula of a carboxylic acid is R–COOH, with R referring to the rest of the (possibly quite large) molecule. Carboxylic acids occur widely and include the amino acids (which make up proteins) and acetic acid (which is part of vinegar and occurs in metabolism). Salts and esters of carboxylic acids are called carboxylates. When a carboxyl group is deprotonated, its conjugate base forms a carboxylate anion. Carboxylate ions are resonance-stabilized, and this increased stability makes carboxylic acids more acidic than alcohols, along with
Sulfonic acid generated readily from benzene. Sulfonic acid A sulfonic acid (or sulphonic acid) refers to a member of the class of organosulfur compounds with the general formula R−S(=O)−OH, where R is an organic alkyl or aryl group and the S(=O)(OH) group a sulfonyl hydroxide. A sulfonic acid can be thought of as sulfuric acid with one hydroxyl group replaced by an organic substituent. The parent compound (with the organic substituent replaced by hydrogen) is the parent sulfonic acid, HS(=O)(OH), a tautomer of sulfurous acid, S(=O)(OH). Salts or esters of sulfonic acids are called sulfonates. A sulfonic acid is produced by the