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COMEDK20269 May 2026Evening ShiftChemistryd and f Block ElementsActual

The product and its colour when MnO₂ is fused with KOH in presence of O₂ :

Options

  1. AK₂ MnO₄ , Dark green
  2. BKMn O₄ , Purple
  3. CMn₂ O₃ , Brown
  4. DMn O₂ , Black

Correct answer

A. K₂ MnO₄ , Dark green

Step-by-step solution

When MnO₂ is fused with KOH in the presence of an oxidizing agent like O₂ or KNO₃ , it forms potassium manganate ( K₂MnO₄ ). The chemical equation for the reaction is: 2MnO₂ + 4KOH + O₂ 2K₂MnO₄ + 2H₂O The product K₂MnO₄ (potassium manganate) is dark green in colour. Answer: K₂ MnO₄ , Dark green

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