Aldehydes, Ketones & Acids · JEE Advanced previous year questions

The major products obtained from the reactions in $\text{List-II}$ are the reactants for the named reactions mentioned in $\text{List-I}$. Match each entry in $\text{List-I}$ with the appropriate entry in $\text{List-II}$ and choose the correct option. List-I (P) Stephen reaction (Q) Sandmeyer reaction (R) Hoffmann bromamide degradation reaction (S) Cannizzaro reaction List-II (1) Toluene $\stackrel{\text{(i) }\mathrm{Cr}{\mathrm{O}}_2\mathrm{C}{\mathrm{l}}_2/C{\mathrm{S}}_2\text{; (ii) }{\mathrm{H}}_3{\mathrm{O}}^{+}}{\to }$ (2) Benzoic acid $\stackrel{\text{(i) }\mathrm{PC}{\mathrm{l}}_5\text{; (ii) }\mathrm{N}{\mathrm{H}}_3\text{; (iii) }{\mathrm{P}}_4{\mathrm{O}}_{10},\Delta }{\to }$ (3) Nitrobenzene $\stackrel{\text{(i) Fe, HCl; (ii) HCl, }\mathrm{NaN}{\mathrm{O}}_2\text{ (273-278 K), }{\mathrm{H}}_2\mathrm{O}}{\to }$ (4) Toluene $\stackrel{\text{(i) }\mathrm{C}{\mathrm{l}}_2/h\nu ,{\mathrm{H}}_2\mathrm{O}\text{; (ii) Tollen’s reagent; (iii) }\mathrm{S}{\mathrm{O}}_2\mathrm{C}{\mathrm{l}}_2\text{; (iv) }\mathrm{N}{\mathrm{H}}_3}{\to }$ (5) Aniline $\stackrel{\text{(i) }(\mathrm{C}{\mathrm{H}}_3\mathrm{CO}{)}_2\mathrm{O}\text{, Pyridine; (ii) }\mathrm{HN}{\mathrm{O}}_3,{\mathrm{H}}_2\mathrm{S}{\mathrm{O}}_4\text{, 288 K; (iii) aq. NaOH}}{\to }$

1. A.P → 2; Q → 4; R → 1; S → 3
2. B.P → 2; Q → 3; R → 4; S → 1
3. C.P → 5; Q → 3; R → 4; S → 2
4. D.P → 5; Q → 4; R → 2; S → 1

Complete reaction of acetaldehyde with excess formaldehyde, upon heating with conc. NaOH solution, gives $\mathbf{P}$ and $\mathbf{Q}$. Compound $\mathbf{P}$ does not give Tollens’ test, whereas $\mathbf{Q}$ on acidification gives positive Tollens’ test. Treatment of $\mathbf{P}$ with excess cyclohexanone in the presence of catalytic amount of $p$-toluenesulfonic acid (PTSA) gives product $\mathbf{R}$. Sum of the number of methylene groups ($-\mathrm{C}{\mathrm{H}}_2-$) and oxygen atoms in $\mathbf{R}$ is ____.