[Pipo87]

Hello

I'm trying to balance the following reaction (in acid):

CH₃CH₂OH + MnO₄^2-  --> CO₂ + Mn²⁺

I can balance the half reaction for manganate (oxidant), that one is easy:

8H⁺ + MnO₄^2- + 4e- <> Mn²⁺ + 4H₂O

But the halfreaction for ethanol (reductant) just doesn't seem right, I can't balance it:

H₂O + CH₃CH₂OH <> 2CO₂ + 8H⁺ + 7e- + 5e-

The mass is balanced this way, but the electric charges aren't, I can't figure out how

Probably should note that I'm a first grade chemistry student, the reaction I'm trying to balance is for school work

Thanks for any help at all!

[Pipo87]

Never mind I missed something completely, and that is that the O's weren't balanced yet
so it's like this:

3H₂O + CH₃CH₂OH <> 2CO₂ + 12H⁺ + 7e- + 5e-

[unsu]

The half-reaction for the permanganate that you wrote is not correct.

[mjc123]

It was manganate, not permanganate. Though the oxidation state diagram that I posted here http://www.chemicalforums.com/index.php?topic=78280.0
would suggest that in acid it is unstable to disproportionation to MnO₄^- and MnO₂.

[Babcock_Hall]

One thing you need to correct is the charge on the permanganate ion.

[Borek]

One thing you need to correct is the charge on the permanganate ion.

As mjc already wrote - question asks for manganate, not permanganate, and the formula of magnanate is OK.

in acid it is unstable to disproportionation to MnO₄^- and MnO₂.

I don't think it matters much for the final answer. While it would mean there are two possible paths for the oxidation, final (overall) reaction equation would be the same.

[unsu]

It was manganate, not permanganate.

Sorry, it did not notice that. Normally people use permanganate to oxidize organic substrates, I never saw anyone using manganate to oxidize the substrates. But anyway, I would like Pipo87 to comment on this to make sure this wasn't a mistake

[Pipo87]

It wasn't a mistake, it really is manganate :p
I also noticed permanganate it much more common, when I tried googling for this reaction before. Actually I did not find any results at all for this reaction with manganate

Though it's not a reaction we used in practice, just a theoretical exercise i had to complete.

Thanks for the feedback anyways, but as I posted before, I managed to find my own silly mistake already

[Babcock_Hall]

It was manganate, not permanganate. Though the oxidation state diagram that I posted here http://www.chemicalforums.com/index.php?topic=78280.0
would suggest that in acid it is unstable to disproportionation to MnO₄^- and MnO₂.

mjc,

How realistic is the question as written?