Question

Which of the following cannot behave as a nucleophile for $S_{N}2$ reaction?

• A. $H_{2}O$
• B. $C{N}^{-}$
• C. $N{H}_2^{-}$
• D. I^-

Answer 1

Answer: (A)

$H_{2}O$ : is a weak nucleophile but a strong base. For $S_{N}2$ reaction, strong nucleophilic reagents are required.