The sodium salt of a carboxylic acid, A, was produced by passing a gas, B, into an aqueous solution of caustic alkali at an elevated temperature and pressure. A on heating in presence of sodium hydroxide followed by treatment with sulphuric acid gave a dibasic acid C, A sameple of 0.4 g of C on combustion gave 0.08g of water and `0.39g` of carbondioxide. The silver salt of acid weihin 1g on ignition yielded 0.71g of silver as residue. Identify A, B and C.

Answer

(A) HCOOH : (B) CO : (C) `underset(COOH)underset(|)COOH`