(a) Explain why : (i) Carboxyl group in benzoic acid is meta directing. (ii) Sodium bisulphite is used for the purification of aldehydes and ketones. (iii) Carboxylic acids do not give characteristic reactions of carbonyl group. OR (b) An organic compound ‘A’, having the molecular formula $\text{C}_3\text{H}_8\text{O}$ on treatment with $\text{Cu}$ at $573 \text{ K}$, gives ‘B’. ‘B’ does not reduce Fehling’s solution but gives a yellow precipitate of the compound ‘C’ with $\text{I}_2/\text{NaOH}$. Deduce the structures of A, B and C.