JEE Main 202621 JanuaryEvening Shift
- Exam
- JEE Main
- Year
- 2026
- Date
- 21 January
- Shift
- Evening Shift
- Subject
- Chemistry
- Chapter
- Haloalkanes and Haloarenes
JEE Main 2026 · 21 January · Evening Shift · Chemistry · Haloalkanes and Haloarenes
The correct order of the rate of the reaction for the following...
The correct order of the rate of the reaction for the following reaction with respect to nucleophiles is :
Options
- A
- B
- C
- D
Correct answer
C.
Step-by-step solution
For the SN2 reaction CH₃Br + Nu⁻, nucleophilicity in aprotic solvents is determined by basicity and polarizability.
⁻OH (hydroxide) is the strongest nucleophile and base, making it highly reactive.
PhO⁻ (phenoxide) is a good nucleophile with reasonable basicity.
CH₃COO⁻ (acetate) is weakened by resonance stabilization of its negative charge across the C-O bonds, reducing its nucleophilicity.
ClO₄⁻ (perchlorate) is a very weak nucleophile, being the conjugate base of a strong acid (HClO₄).
The correct order of nucleophilicity is: ⁻OH > PhO⁻ > CH₃COO⁻ > ClO₄⁻, which matches option (3).
⁻OH (hydroxide) is the strongest nucleophile and base, making it highly reactive.
PhO⁻ (phenoxide) is a good nucleophile with reasonable basicity.
CH₃COO⁻ (acetate) is weakened by resonance stabilization of its negative charge across the C-O bonds, reducing its nucleophilicity.
ClO₄⁻ (perchlorate) is a very weak nucleophile, being the conjugate base of a strong acid (HClO₄).
The correct order of nucleophilicity is: ⁻OH > PhO⁻ > CH₃COO⁻ > ClO₄⁻, which matches option (3).