(S)-CH3CH(N3)CH2CH2CH3 can be synthesized by an SN2 reaction. Draw the structures of the alkyl chloride and nucleophile that will give this compound in highest yield.

See explanation and image attached

Explanation:

Let us recall that the reaction in question is expected to happen by SN2 mechanism. This is because, the reaction occurs at secondary carbon atom and the attacking nucleophile (N3^-) is a good nucleophile.

The reaction occurs via a backside attack of the N3^- ion on (R)-2-chloropentane. This backside attack leads to inversion of configuration at the reaction centre to yield (S)-CH3CH(N3)CH2CH2CH3.

The images of the alkyl halide and nucleophile are shown in the image attached to this answer.