Stability in Aqueous Systems
Disproportionation Reactions
- A substance reacts with itself to form new substances with higher and lower oxidation numbers.
No examples with V or Cr.
MnO42- will disproportionate:
- MnO4-(aq) + e- ? MnO42-(aq) E°red = +0.56 V
- MnO42-(aq) + 4H+(aq) + 2e- ? MnO2(s) + 2H2O(l) E°red = +2.26 V
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- 3MnO42- + 4H+ ? 2MnO4- + MnO2 + 2H2O Eorxn = 1.70 V