Question

Out of $C_6{H}_{5}C{H}_{2}Cl$ and $C_6{H}_{5}C{H}^{}Cl{C}_6{H}_5$ which is more easily hydrolysed by aqueous $KOH$?

Answer 1

$C_6{H}_5-{CH}_2-Cl\underset{-{Cl}^{-}}{⟶}{C}_6{H}_5-{\stackrel{+}{CH}}_2$

Benzyl chloride $\left(1^0\right)$ $1^0$ carbocation

Hydrolysis by aqeous $KOH$ proceeds through formation of carbocation. If carbocation is stable, the more is hydrolysed by aq. $KOH$, Now,

$C_6{H}_5{CH}_{2}Cl$ forms $1^0$ carbocation

$C_6{H}_5\underset{|}{CH}-C_6{H}_5$ forms $2^0$ carbocation

$Cl$

Stability of carbocations $2^0>1^0$

Thus, ${\left(C_6{H}_5\right)}_2-CH-Cl$ is hydrolysed more easily than $C_6{H}_5-{CH}_2-Cl$ by aqeous $KOH$.