Question

Which of the following is not a nucleophile?

• A. $O{H}^{-}$
• B. $C{N}^{-}$
• C. $B{F}_3$
• D. $N{H}_3$

Answer 1

The correct option is C $B{F}_3$

A reagent which donates an electron pair to an electron deficient centre (except $H^{+}$) is called as a nucleophile.
$N{H}_3,O{H}^{-},C{N}^{-}$ can donate electron pair, thus they are nucleophiles while $B{F}_3$ can only accept an electron pair in its vacant p-orpital and thus it acts as an electrophile.