Need help using Ion Electron Method in acidic conditions.

by thyrgle
Tags: acidic, conditions, electron, method
thyrgle is offline
Oct26-11, 10:20 PM
P: 9
Using the Ion Electron Method (acidic conditions) I need to solve:

MnO4- + C2O42- -> Mn2+ + CO2

So I tried doing:

MnO4- -> Mn2+


C2O42- -> CO2 + 2H2O

Then I balanced the oxygen atoms with H2O

MnO4- -> Mn2+ + 4H2O


C2O42- -> CO2 + 2H2O

Then I added the hydrogen atoms:

MnO4- + 8H+ -> Mn2+ + 4H2O


C2O42- + 4H+ -> CO2 + 2H2O

Then I tried balancing the electrons and I got -3e for the first equation and -2e for the second. Then I tried combining the two:

2MnO4- + 16H+ +
3C2O42- + 12H+ -> 2Mn2+ + 8H2O + 3CO2 + 6H2O

Cancel out the H+ and H2O:

2MnO4- + 28H+ +
3C2O42- -> 2Mn2+ + 14H2O + 3CO2

I don't know if there is something else I should do (which I suspect there is but I can't tell), and I think I am doing something wrong because my answer didn't turn out right. Any help would be appreciated.
Phys.Org News Partner Chemistry news on
First view of nature-inspired catalyst after ripping hydrogen apart provides insights for better, cheaper fuel cells
Following a protein's travel inside cells is key to improving patient monitoring, drug development
Team helps cancer treatment drugs get past their sticking point
Borek is offline
Oct27-11, 02:45 AM
Borek's Avatar
P: 22,710
Quote Quote by thyrgle View Post
C2O42- -> CO2 + 2H2O
You should balance carbon first. H2O - if needed - should appear in the next step.

Register to reply

Related Discussions
Why are acidic amino acid side chains acidic? Chemistry 4
boundary conditions for Alternating directions implicitly method Differential Equations 0
stability conditions for finite difference method to solve coupled equations Differential Equations 0
Trouble with boundary conditions in Newton-Raphson method for Coupled PDEs Differential Equations 0
determination of e/m of electron by magic eye method Introductory Physics Homework 1