JEE Main 202628 JanuaryEvening Shift
- Exam
- JEE Main
- Year
- 2026
- Date
- 28 January
- Shift
- Evening Shift
- Subject
- Chemistry
- Chapter
- Carboxylic Acid Derivatives
JEE Main 2026 · 28 January · Evening Shift · Chemistry · Carboxylic Acid Derivatives
The correct order of acidic strength of the major products formed...
The correct order of acidic strength of the major products formed in the given reactions, is :
A.
B.
C.
D.
Choose the correct answer from the options given below :
A.
B.
C.
D.
Choose the correct answer from the options given below :
Options
- A
- B
- C
- D
Correct answer
B.
Step-by-step solution
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 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).
Product [B]: From CH₃CH₂CHO, Tollens' oxidation with 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).