Question
The correct order of reactivity of CH _ 3 Br in methanol with the following nucleophiles is F ^ - , I ^ - , C _ 2 H _ 5 O ^ - and C _ 6 H _ 5 O ^ -
The correct order of reactivity of CH _ 3 Br in methanol with the following nucleophiles is F ^ - , I ^ - , C _ 2 H _ 5 O ^ - and C _ 6 H _ 5 O ^ -
B. I ^ - > C _ 2 H _ 5 O ^ - > C _ 6 H _ 5 O ^ - > F ^ -
In methanol (protic solvent), nucleophilicity is determined by basicity and solvation effects. Smaller ions are heavily solvated by the protic solvent, reducing their effective nucleophilicity. C₂H₅O⁻ (ethoxide) is the strongest nucleophile as it is less solvated and highly basic. C₆H₅O⁻ (phenoxide) is weaker due to resonance stabilization by the benzene ring. F⁻ is highly solvated despite high basicity, reducing its nucleophilicity significantly. I⁻ is the best nucleophile because it is the largest ion and least solvated in methanol. The correct order is I⁻ > C₂H₅O⁻ > C₆H₅O⁻ > F⁻.
Related: Chemistry — Haloalkanes and Haloarenes · All PYQ Banks