Question

Which of the following reactions will go faster if the concentration of the nucleophile is increased?

• A.
• B.
• C.
• D.

Answer 1

The correct option is A

The given reactions are substitution reactions. The rate is affected by the concentration of nucleophile in $S_{N}2$ reactions. Since (a) undergoes substitution most readily through $S_{N}2$ mechanism, increasing the concentration of the nucleophile would increase the rate of the reaction.

Rest of the reactions given, proceeds via the $S_{N}1$ pathway, since they are able to form stable intermediates.