Answer:
See explanation
Explanation:
SN2 reaction is a synchronous reaction in which the leaving group departs as the nucleophile is being attached to the substrate in a single step. This makes it imperative to use a good leaving group when carrying out an SN2 reaction such as the one shown in the question.
The addition of a small amount of NaI acts as a sort of external nucleophile which assists the departure of the leaving group thereby enabling the reaction to proceed faster. This occurs because the iodide ion is very good leaving group.