Identify the major products formed in the following reaction sequences and arrange them in the decreasing order of their acidic strength: (A) p -Toluidine [ (ii) CuCN ] (i) NaNO ₂, HCl , 0-5^ C H ₃ O ⁺/ Product A (B) o -Toluidine [ (ii) CuCN ] (i) NaNO ₂, HCl , 0-5^ C H ₃ O ⁺/ Product B (C) Phenol [ (ii) H ⁺] (i) CHCl ₃, aq. NaOH , [ (iv) H ⁺] (iii) [ Ag ( NH ₃)₂]⁺, OH ⁻ Product C (D) Aniline [ (ii) CuCN ] (i) NaNO ₂

Step-by-step solution

Product A: Diazotization of p -toluidine followed by Sandmeyer reaction with CuCN gives p -tolunitrile, which on hydrolysis yields p -toluic acid. Product B: Similar reactions on o -toluidine yield o -toluic acid. Product C: Reimer-Tiemann reaction of phenol yields salicylaldehyde as the major product. Oxidation of the aldehyde group by Tollens' reagent followed by acidification gives salicylic acid. Product D: Aniline undergoes similar reactions to yield benzoic acid. Comparing acidic strengths: Salicylic acid (C)