Out of `C_(6)H_(5)CH_(2)Cl` and `C_(6)H_(5)CHClC_(6)H_(5)`, which is more easily hydrolysed by aqueous KOH.

Explanation

`C_(6)H_(5)CH_(2)CI` is a `1^(@)` aralkyl halide and `C_(6)H_(5)CHCIC_(6) H_(5)` is a `2^(@)` aralkyl halide. In `S_(N)1` reaction, the reaction proceeds through the formation of carbocation. In the first step, the aralkyl halide ionizes to give carbocation:

The carbocation (II) is more stable than (I) because the +ve charge on carbon can be delocalised over two benzene rings. On the other hand, the +ve charge in carbonation (I) is delocalised over only one benzene ring. Therefore, `C_(6)H_(5)CHCIC_(6) H_(5)` can be more easily hydrolysed than `C_(6)H_(5)CH_(2)CI` in `S_(N)1` reactions. However in `S_(N)2` reactions, the reactivity depends uponthe steric hindrance. Therefore, `C_(6)H_(5)CH_(2)CI` will get hydrolysed more easily than `C_(6)H_(5)CHCIC_(6) H_(5)` because of less steric hindrance.