Ncert Exercises & Solutions

Identify the reagents shown in bold in the following equations as nucleophiles or
electrophiles:

1. OH⁻ = nucleophile, CN⁻ = nucleophile, and CH₃CO⁺ = electrophile.

2. OH⁻ = electrophile, CN⁻ = nucleophile, and CH₃CO⁺ = electrophile.

3. OH⁻ = electrophile, CN⁻ = electrophile, and CH₃CO⁺ = electrophile.

4. OH⁻ = nucleophile, CN⁻ = nucleophile, and CH₃CO⁺ = nucleophile.

Hint:

Electrophiles are electron-deficient species and can receive an electron pair. On the other

hand, nucleophiles are electron-rich species and can donate their electrons.

Explanation:

(a) $C H_{3} C O O H + H O^{-} \to C H_{2} C O O^{-} + H_{2}$

Here, HO $^{-}$ acts as a nucleophile as it is an electron-rich species, i.e., it is a nucleus seeking
species.

(b) $C H_{3} C O C H_{3} + \bar{C} N \to {(C H_{3})}_{2} C (C N) + (O H)$

Here, $^{-}$ CN acts as a nucleophile as it is an electron-rich species, i.e., it is a nucleus seeking
species

Here, $C H_{3} \overset{+}{C O}$ acts as an electrophile as it is an electron-deficient species.