JEE Main 2026 Jan 22 Shift 1, Chemistry Q9: Properties of Alkyl Halides (Halo Alkanes) & Aryl Halides (Halo Arenes)

The solvent (methanol) is protic, so nucleophilicity rankings follow polarisability and basicity in a protic medium:

$I^{-}$ is the largest, most polarisable, and the least solvated — the strongest nucleophile here despite being a weak base.

$C_2{H}_5{O}^{-}$ is a strong base with localised negative charge — a good nucleophile.

$C_6{H}_5{O}^{-}$ has its charge delocalised into the aromatic ring, so it’s weaker than $C_2{H}_5{O}^{-}$.

$F^{-}$ is small and tightly H-bonded by methanol, so it’s the poorest of the four.

Overall: $I^{-}>C_2{H}_5{O}^{-}>C_6{H}_5{O}^{-}>F^{-}$.