Answer:
C) MnO₂
Explanation:
If we write the semi equations (this is, for reduction and oxidation) we will have:
Oxidation: 2MnO₂ → MnO₄⁻ + Mn⁺²
Reduction: 2H₂O → H₂ + 2OH⁻
Then the final global reaction (just adding the two above hemi chemical reactions):
2MnO₂ + 2H₂O → MnO⁻₄ + Mn⁺² + H₂ + 2OH⁻ (in acidic media)
So, we have Mn⁺⁴ (from MnO₂) goes to Mn⁺⁷ and Mn⁺² (this is, Mn is oxidated) and H⁺ (from acidic media or H₂O) goes to H₂ (this is, it is reduced). So the reducing agent would be MnO₂
Density<span> is </span>defined<span> as the ratio between mass and volume or mass per unit volume.
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