Answer:
3-chloro-3-methylpentane,>2-chloro-3-methylpentane> 1-chloro-3-methylpentane, > chloromethane
Explanation:
The rate of SN1 reactions decreases in the order, tertiary > secondary > primary > methyl.
This implies that, a tertiary alkyl halide is better able to undergo nucleophilic substitution by SN1 mechanism compared to a secondary, primary or methyl.
This is because, the transition state leading to the formation of an SN1 product involves a carbocation. The order of stability of carbocations is; tertiary > secondary > primary > methyl.
Hence a tertiary alkyl halide such as 3-chloro-3-methylpentane leads to a more stable transition state and undergoes SN1 reaction at a faster rate.
