Question

The decreasing order of nucleophilicity among the nucleophiles
[2005]
(A) $C{H}_3\underset{\underset{O}{|}|}{C}-O^{-}$
(B) $C{H}_3{O}^{-}$
(C) $C{N}^{-}$
(D)

• A. (C), (B), (A), (D)
• B. (B), (C), (A), (D)
• C. (D), (C), (B), (A)
• D. (A), (B), (C), (D)

Answer 1

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

In moving down a group, the basicity and nucleophilicity are inversely related, i.e., nucleophilicity increases while basicity decreases. In going from left to right across a period, the basicity and nucleophilicity are directly related. Both of the characteristics decrease as the electronegativity of the atom bearing lone pair of electrons increases. If the nucleophilic centre of two or more species is same, nucleophilicity parallels basicity, i.e. more basic the species, stronger is its nucleophilicity. Hence based on the above facts, the correct order of nucleophilicity will be