Give the order of reactivity towards `SN^(-1)` solvoloysis of the following:
i. Benzyl chloride
ii. `p-` Chlorobenzyl chloride
iii. `p-` Methoxbenzyl chloride iv. `p-` Methyl benzyl chloride
v. `p-` Nitrobenzyl chloride

Explanation

`(iii) gt (iv) gt (i) gt (ii) gt (v)`. Solovolysis means the replacement of `Cl` by solvent anion. In `SN^(1)` mechanism, a carboacation decideds the reactivityy.
An electron donatng group increases the stabilty and hence reactivtiy, while electron-withdrawing group decreases teh stability (and hence reactivity) but in `(iv)`, the stability of benzyl `C^(o+)` is due to hyperconjugation. `+R` and `-I` effects of the `(-OMe)` group are stronger than `+I` and `H.C`. effects of the `(Me)` group.