Chemistry - Halogen Derivative Question with Solution | TestHub

$\left({\mathrm{C}}_6{\mathrm{H}}_5\right)\mathrm{C}\mathrm{C}\mathrm{l}\mathrm{}\stackrel{{\mathrm{S}}_{{\mathrm{N}}^1}}{\to }\mathrm{}\left({\mathrm{C}}_6{\mathrm{H}}_5\right){\mathrm{C}}^{\oplus }$
Rate of${\mathrm{S}}_{{\mathrm{N}}^1}$rection$\propto$stability of carbocation
Stability of carbocation
(1)$\mathrm{C}{\mathrm{H}}_3-\mathrm{C}\mathrm{H}=\mathrm{C}{\mathrm{H}}^{+}$+ve${\mathrm{C}}_{{\mathrm{s}\mathrm{p}}^2}\mathrm{}$
(2)$\stackrel{\oplus }{\mathrm{C}}{\mathrm{H}}_2-\mathrm{C}\mathrm{H}={\mathrm{C}\mathrm{H}}_2$+ve change in configuration
$\left(3\right)$+ve change is more delocalized in benzene ring
(4)highly stable due to +ve charge is more delocalised
Stability of carbocation: -$4>3>2>1$
Higher rate of${\mathrm{S}}_{{\mathrm{N}}^1}$reaction in (4)${\left(\mathrm{P}\mathrm{h}\right)}_3\mathrm{C}-\mathrm{C}\mathrm{l}$