Question

Which is stronger oxidising agent: S₂O₈²⁻ or KMnO₄ ? and why : #NoSpamming

Answer 1

We know that In KMnO₄ the Mn charge = +7,

On writing the reaction in acidic , neutral and basic medium.

(i)So reaction occurs in acidic medium :-

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MnO₄⁻ + 8 H⁺ + 5 e⁻ ----→ Mn²⁺ + 4H₂O

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As you see here , Mn gives up 5 e⁻ . (Making this as a strong oxidizing agent)

(ii) So reaction occurs in Neutral medium :-

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MnO₄⁻ + 4H⁺ + 3 e⁻ ------→ MnO₂ + 2H₂O

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As you can see here , In this neutral solution, it gives up 3 e⁻ in formation of MnO₂ & also some OH ions.

(ii) So reaction occurs in Basic medium :-

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MnO₄⁻ + e⁻ -----→ MnO₄²⁻

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As you can see here, it only gives up 1 e⁻ , So it makes it weaker oxidizing agent.

Hence we can simply observe here :-

MnO₄⁻ ion → Acidic solution > Neutral solution > Basic solution.

Hence it is strong oxidising agent in acidic medium.

Hope it Helps :-)