The correct order of acidic strength of the major products formed in the given reactions, is : A. B. CH _ 3 CH _ 2 CHO [ ] [ Ag ( NH _ 3 )_ 2 ]^ + , OH ^ - [ B ] C. CH _ 4 + O _ 2 [ (ii) Na _ 2 Cr _ 2 O _ 7 / H ^ + ] (i) [ C ] D. PhCH _ 2 MgBr + CO _ 2 [ H _ 3 O ^ + ] Dry ether [ D ] Choose the correct answer from the options given below :
B. C>A>D>B
Product [A]: From PhNH₂, steps (1) NaNO₂ + HCl forms diazonium salt, (2) CuCN gives benzonitrile, (3) H₃O⁺/Δ hydrolyzes to benzoic acid (PhCOOH), pKa ≈ 4.2. Product [B]: From CH₃CH₂CHO, Tollens' oxidation with [Ag(NH_3)_2]^+ produces acetic acid (CH₃COOH), pKa ≈ 4.8. Product [C]: From CH₄ + O₂ with heat and Na₂Cr₂O₇/H⁺ produces formic acid (HCOOH), pKa ≈ 3.8 (strongest acid). Product [D]: From PhCH₂MgBr + CO₂, the Grignard reaction produces phenylacetic acid (PhCH₂COOH), pKa ≈ 4.3. Acidic strength order (lower pKa = stronger): C (3.8) > A (4.2) > D (4.3) > B (4.8).
Related: Chemistry — Carboxylic Acid Derivatives · All PYQ Banks