A primary alkyl halide would prefer to undergo :-

Options

A. `S_N^1` reaction
B. `S_N^2` reaction
C. `alpha`- elimination
D. Racemisation

Answer

B

Explanation

(b) A primary alkyl halide would prefer to undergo `S_N^2` reaction.
(a) `S_N^2` reactions occur only if the intermediate carbocation is stable i.e., `3^@` carbocation.
(b) `S_N^2` reactions occur if there is less steric hinderance on to the `alpha`-carbon of alkyl halide. In case of primary alkyl halides, carbocation is highly unstable and steric hinderance is very less. So, primary alkyl halide would prefer to undergo `S_N^2` reaction.
(c) In `alpha` -elimination, proton and the leaving group are present on same atom.
(d) Racemisation is the process of conversion of enantiomer into a racemic mixture.