question_answer

The decreasing order of nucleophilicity among the nucleophiles (A)\[C{{H}_{3}}\underset{\begin{smallmatrix}  |\,| \\  O \end{smallmatrix}}{\mathop{C}}\,-{{O}^{-}}\]                    (B) \[C{{H}_{3}}{{O}^{-}}\] (C) \[C{{N}^{-}}\] (D)     AIEEE  Solved  Paper-2005

A) (C), (B), (A), (D)   

B)        (B), (C), (A), (D)

C)                        (D), (C), (B), (A)  

D)       (A), (B), (C), (D)

Correct Answer: B

Solution :

If acid is weak, its conjugate base (nucleophile) is strong and vice-versa. \[C{{H}_{3}}-\overset{\begin{smallmatrix}  O \\  |\,| \end{smallmatrix}}{\mathop{C}}\,-{{O}^{-}}\]is a conjugate base of        \[\overset{\begin{smallmatrix}  O \\  |\,| \end{smallmatrix}}{\mathop{C{{H}_{3}}COH}}\,(I)\] \[C{{H}_{3}}{{O}^{-}}\]is a conjugate base of\[C{{H}_{3}}OH\](II) \[C{{N}^{-}}\]is a conjugate base of\[HCN\](III)   is a conjugate base of  (IV) Acidic nature of\[IV>I>III>II\] and nucleophilicity of\[B>C>A>D\]