The decreasing order of nucleophilicity for the following anions is CH₃CO₂⁻, CH₃O⁻, C₆H₄O⁻, NO₃⁻ · ABC26OR0749

Subject: Organic Chemistry · Chapter: Stereochemistry · Topic: Stereochemistry – General · Exam: GATE 2000-2022 · Marks: 2 · Difficulty: Medium

The decreasing order of nucleophilicity for the following anions is $\mathrm{CH}_{3}\mathrm{CO}_{2}^{-}, \mathrm{CH}_{3}\mathrm{O}^{-}, \mathrm{C}_{6}\mathrm{H}_{4}\mathrm{O}^{-}, \mathrm{NO}_{3}^{-}$
(a)$\mathrm{CH}_{3}\mathrm{CO}_{2}^{-}>\mathrm{CH}_{3}\mathrm{O}^{-}>\mathrm{C}_{6}\mathrm{H}_{5}\mathrm{O}^{-}>\mathrm{NO}_{3}^{-}$
(b)$\mathrm{CH}_{3}\mathrm{O}^{-}>\mathrm{NO}_{3}^{-}>\mathrm{C}_{6}\mathrm{H}_{5}\mathrm{O}^{-}>\mathrm{CH}_{3}\mathrm{CO}_{2}^{-}$
(c)$\mathrm{CH}_{3}\mathrm{O}^{-}>\mathrm{C}_{6}\mathrm{H}_{5}\mathrm{O}^{-}>\mathrm{CH}_{3}\mathrm{CO}_{2}^{-}>\mathrm{NO}_{3}^{-}$
(d)$\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{O}^{-}>\mathrm{CH}_{3} \mathrm{O}^{-}>\mathrm{NO}_{3}^{-}>\mathrm{CH}_{3} \mathrm{CO}_{2}^{-}$
Answer
Answer: C ✓ checked by 4AB · confidence high

The source book printed D; on checking, C is correct — see the explanation.

Explanation
Nucleophilicity parallels basicity for these oxygen anions: CH₃O⁻ (pKa 16) > C₆H₅O⁻ (10) > CH₃CO₂⁻ (4.8) > NO₃⁻ (−1.4).

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