Question

Which of the following alkyl halides undergoes $S_{N}1$ reaction the fastest?

• A. methyl chloride
• B. ethyl chloride
• C. isobutyl chloride
• D. tert-butyl chloride

Answer 1

The correct option is D tert-butyl chloride

Tert-Butyl chloride will form $3^o$ carbocation which is the most stable carbocation.

and order of Reactivity for $S_{N^1}$ will be

$3^o>2^o>>1^o$

Therefore, Answer is tert-butyl chloride