Chemistry - Halogen Derivative Question with Solution | TestHub

The reactivity of the alkyl halide is decided by the ease with which the halide leaves the substrate. As with the decrease in size of halogen, C – X bond energy increases and so reactivity of alkyl halide decreases.
It means the leaving ability, order is${\mathrm{I}}^{-}>\mathrm{B}{\mathrm{r}}^{-}>\mathrm{C}{\mathrm{l}}^{-}>{\mathrm{F}}^{-}$and the order of${\mathrm{S}}_{\mathrm{N}}2$​ reaction is RI > RBr > RCl > RF.