JEE Main202621 January 2026Evening ShiftChemistryHaloalkanes and HaloarenesActual
The correct order of the rate of the reaction for the following reaction with respect to nucleophiles is : CH ₃ Br + Nu ^ CH ₃ Nu + Br ^
Options
- APhO ⁻> ⁻ OH > CH ₃ COO ⁻> ClO ₄⁻
- BCH ₃ COO ⁻> PhO ⁻> ⁻ OH > ClO ₄⁻
- C⁻ OH > PhO ⁻> CH ₃ COO ⁻> ClO ₄⁻
- DClO ₄⁻> CH ₃ COO ⁻> ⁻ OH > PhO ⁻
Correct answer
C. ⁻ OH > PhO ⁻> CH ₃ COO ⁻> ClO ₄⁻
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 nucle