An organic compound of molecula formula `C_(6)H_(5)O"Na"` is heated with `CO_(2)` at 400 K gives compound (A) of molecular formula `C_(7)H_(5)O_(3)Na`. Compound (A) on treating with HCl gives (B). B on further reactions wiith NaOH / CaO gives compound (C ) of molecular formula `C_(6)H_(6)O` which on treatment with nitrous acid at 200 K gives compound (D ). Identify (A), (B) , ( C) and (D) are explain the reactions.

Explanation

(i) When a sodium phenoxide is heated with carbon dioxide at 400 K under pressure, sodium salicylate is formed.

(ii) Sodium salicylate is decomposed hydilute hydrochloric acid, when salicylic acid is formed.

(iii) On treatment with NaOH/ CaO sodium salicyalte gives phenol.

(iv) Phenol reacts with nitrous acid to give p-nitrosophenol.