Paragraph IV
There are several factors which decide the fate of substrate in presence of nucleophile. One of them is nature of solvent.
In mildly basic, neutral or acidic solution primarily substitution takes place. This will occur via `S_N2` mechanism for 1° alkyl halides and via `S_N1` mecahanism for 3° alkyl halides. When 2° alkyl halides react with(-) charge nucleophile in polar protic solvents, the `S_N2` mechanism is followed when 2° alkyl halides react with `H_2O` or ROH as solvent `S_N1` mechanism is followed.
In strongly basic solutions primarily elimination takes place with 2° and 3° alkyl halides. When we use strong and sterically hindered base, KOtBu, even 1° alkyl halides given elimination products primarily.
`CH_3-underset(Br)underset(|)(CH)-CH_3overset(Na^(+)N_3^(-) "Acetone")`to A , product A is

Options

A. `CH_3CH = CH_2`
B. `CH_3-CH_2-CH_2-N_3`
C. `CH_3-underset(N_3)underset(|)(CH)-CH_3`
D.

Answer

C

Explanation

Polar solvent so via `S_N2` reaction-`N_3` will get substitute on `2^@`alkyl halide.