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Simple Redox Balancing, need confirmation

  1. Oct 14, 2012 #1


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    Cr2O72- + H2O2 → Cr3+ + O2

    Cr2O72- + 3H2O2 + 8H+ → 2Cr3+ + 3O2 + 7H2O

    Is my attempt correct. I think I had lost my grip in redox balancing.
  2. jcsd
  3. Oct 14, 2012 #2


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    Balancing reactions with hydrogen peroxide if oxygen and water are between products is always tricky, as these are products of the hydrogen peroxide decomposition. That means you can always combine your reaction with hydrogen decomposition reaction and you will still get something that is - from the formal point of view - correctly balanced, but it doesn't reflect any real reaction.

    You can try to assume that oxygen produced has the sole source of hydrogen peroxide, that's the approach that yields correct results in the case of the reaction between hydrogen peroxide and permanganate. But just because it yields a correct result doesn't mean that's what is really happening - observed stoichiometry can agree with this approach just accidentally.

    Compare http://pubs.acs.org/doi/abs/10.1021/ic00224a030
  4. Oct 15, 2012 #3


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    Yeah. This questions seems to have infinite solutions. That's the base equation I got. There's a parallel disproportionation of Hydrogen Peroxide going on, so I guess I screwed up nonetheless.
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