10.8 In the following pairs of halogen compounds, which compound undergoes faster reaction?
(ii)
In reactions, the formation of carbocation takes place and this is the rate-determining step for these kinds of reactions. So the compound that forms the more stable carbocation will react faster. So tertiary carbonation is more stable than secondary and secondary carbonation is more stable than primary carbonation. Hence 2-chloroheptane forms secondary carbocation and Chlorohexane forms primary carbonation as intermediate.
So 2-chloroheptane gives SN1 reaction faster.