Which alkyl halide would you expect to undergo an S_N2 reaction most slowly?

Question

Quizplus · Accepted Answer

The rate of an SS1 reaction depends on the stability of the carbocation intermediate formed. The more stable the carbocation, the faster the reaction. In this case, the reaction rate will be slowest for the alkyl halide that forms the most unstable carbocation intermediate. Out of the options given, the alkyl halide that forms the most unstable carbocation intermediate is 1-bromo-2,2-dimethylbutane (E) due to the presence of two bulky methyl groups. Therefore, it is expected to undergo the S_N2 reaction most slowly.

Which Alkyl Halide Would You Expect to Undergo an SN2

Which Alkyl Halide Would You Expect to Undergo an S_N2