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# Stupid balancing equation watch

1. Can someone please explain to me why this balancing equation isnt 2MnO4^2- + 4H^+ ➡️2MnO4^- + MnO2 + 2H2O. I think its something to do with the charges on the manganese and oxygen compounds but i dont know why.
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2. (Original post by theA-Levelflop)
Can someone please explain to me why this balancing equation isnt 2MnO4^2- + 4H^+ ➡️2MnO4^- + MnO2 + 2H2O. I think its something to do with the charges on the manganese and oxygen compounds but i dont know why.
Do you know what the actual answer is? Because it looks right to me. I would probably have just put a 1 before the MnO2 molecule (just so that it doesn't look like it's been left blank) - the charges and numbers of atoms look perfectly balanced to me...
3. (Original post by mupsman2312)
Do you know what the actual answer is? Because it looks right to me. I would probably have just put a 1 before the MnO2 molecule (just so that it doesn't look like it's been left blank) - the charges and numbers of atoms look perfectly balanced to me...
The answer in the attachment is the answer that's given in the mark scheme but I don't see what is wrong with the way I said in the thread starter.
4. I don't think the oxygen is balanced
5. (Original post by mariejuana)
I don't think the oxygen is balanced
It's balanced both ways
6. (Original post by theA-Levelflop)
The answer in the attachment is the answer that's given in the mark scheme but I don't see what is wrong with the way I said in the thread starter.
Look at the Mn atoms in your answer - you've gone from 2 to 3. You've also gone from 8 to 12 O atoms.

So, basically, you've increased by 1 Mn and and 4 O atoms from left to right; that means that you need one extra MnO4^2- ion on the LHS to balance the equation fully.
7. (Original post by mupsman2312)
Look at the Mn atoms in your answer - you've gone from 2 to 3. You've also gone from 8 to 12 O atoms.

So, basically, you've increased by 1 Mn and and 4 O atoms from left to right; that means that you need one extra MnO4^2- ion on the LHS to balance the equation fully.
I've just realised why its the answer in the attachment. In the thread starter, the overall charge on the LHS is 0 and -2 on the RHS but in the attachment, the charge on both sides is -2.
Plus you're right about the Mn but thats just a typo.
8. (Original post by theA-Levelflop)
Can someone please explain to me why this balancing equation isnt 2MnO4^2- + 4H^+ ➡️2MnO4^- + MnO2 + 2H2O. I think its something to do with the charges on the manganese and oxygen compounds but i dont know why.
Work out the oxidation states of all of the Mn atoms, they also need to balance.

If there is a change in O.S.s there must be the gain of loss of e-.
9. (Original post by thea-levelflop)
can someone please explain to me why this balancing equation isnt 2mno4^2- + 4h^+ ➡️2mno4^- + mno2 + 2h2o. I think its something to do with the charges on the manganese and oxygen compounds but i dont know why.
Attachment 730566
algebra to the rescue
Attached Images

10. (Original post by mupsman2312)
Do you know what the actual answer is? Because it looks right to me. I would probably have just put a 1 before the MnO2 molecule (just so that it doesn't look like it's been left blank) - the charges and numbers of atoms look perfectly balanced to me...
The equation is

3 MnO4^2- + 4H+ -> 2MnO4^- + MnO2 + 2H2O
just like you said
the charges are perfectly balanced in the question . But the stochiometry coefficient wasn't. The equation looked puzzling at first like a brainteaser.
11. (Original post by dip0)
The equation is

3 MnO4^2- + 4H+ -> 2MnO4^- + MnO2 + 2H2O
just like you said
the charges are perfectly balanced in the question . But the stochiometry coefficient wasn't. The equation looked puzzling at first like a brainteaser.
Yes, my mistake - I was talking about the answer in the attachment (I didn't realise that this was the mark scheme). I probably should have read the full original post before replying...

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