Question

Arrange the following nucleophiles in the decreasing order of nucleophilicity :
(A) $C{H}_3\underset{O}{\underset{||}{C}}-O^{-}$

(B) $C{H}_3{O}^{-}$

(C) $C{N}^{-}$

(D) Ref. image

• A. C , B , A , D
• B. A , B , C , D
• C. D , C , B , A
• D. B , C , A , D

Answer 1

The correct option is D B , C , A , D

Conjugate base (nucleophile) is strong if acid is weak and vice-versa.
A) $C{H}_3\underset{O}{\underset{||}{C}}-O^{-}$ is a conjugate base of $C{H}_3\underset{O}{\underset{||}{C}}-OH$ (I).
B) $C{H}_3{O}^{-}$ is a conjugate base of $C{H}_{3}OH$ (II).
C) $C{N}^{-}$ is a conjugate base of HCN (III).
D) $p-H_{3}C-C_6{H}_4-S{O}_2-O^{-}$ is conjugate base of $p-H_{3}C-C_6{H}_4-S{O}_2-OH$(IV).
Order of acidic nature is $IV>I>III>II$.
Hence, the decreasing order of nucleophilicity is $B>C>A>D$.