The correct order of increasing reactivity of C-X bond towards nucleophile in the following compounds is :

Options

A. `I lt II lt IV lt III`
B. `II lt III lt I lt IV`
C. `IV lt III lt I lt II`
D. `III lt II lt I lt IV`

Answer

A

Explanation

Key Idea Alkyl halides are more reactive towards nucleophilic substitution. Reactivity depends upon the stability of carbocation intermediate formed.
Among the given halides, aryl halide `(C_(6)H_(5)X)` is least reactive towards nucleophile as in it the C-X bond acquire some double bond character due to resonance. Presence of electron withdrawing groups like `-NO_(2)` at ortho and para-positions facilitate the nucleophilic displacement of -X of aryl halide. Among alkyl halides, `3^(@)` halides are more reactive as compared to `2^(@)` halides due to the formation of more stable carbocation. Hence, the order of reactivity of C-X bond towards nucleophile is as follows :