\(\text{Hydrolysis by aqueous \(KOH\)}\)
The reaction mechanism involved here is \(S_N1\) type and rate of \(S_N1\) reaction depends on stability of carbocation intermediate.
Hydrolysis by aqueous \(KOH\) proceeds through the formation of carbocation. If carbocation is stable, then the compound is easily hydrolyzed by aqueous \(KOH\).
\(C_6H_5CH_2Cl\) forms \(1^{\circ}\) carbocation, which is resonance stabilized by benzene ring.
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/1591551/original_35.png)
\(C_6H_5CHClC_6H_5\) forms \(2^{\circ}\) carbocation, which is resonance stabilized by two benzene rings.
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/1591569/original_35s.png)
Since \(2^{\circ}\) carbocation is more stable than \(1^{\circ}\) carbocation and also, we can say that \(1^{\circ}\) carbocation is stabilized by one benzene ring and \(2^{\circ}\) carbocation is stabilized by two benzene rings through resonance.
Hence, \(C_6H_5CHClC_6H_5\) is hydrolyzed more easily than \(C_6H_5CH_2 Cl\) by aqueous \(KOH\).