Complete and balance the following redox reaction in basic solution

Question

MnO4- + C2O4-2 > MnO2 +Co2

Answer 1

Half reactions:

MnO₄^- ==> MnO₂ .. unbalanced reduction reaction

MnO₄^- ==> MnO₂ + 2H₂O.. balanced for Mn and O

MnO₄^-+ 4H₂O ==> MnO₂ + 2H₂O + 4OH^- .. balanced for Mn, O and H (using base, OH-)

MnO₄^-+ 4H₂O + 3e- ==> MnO₂ + 2H₂O + 4OH^- .. balance for Mn, O, H, and charge = balanced eq.

C₂O₄^2- ==> CO₂ .. unbalance oxidation reaction

C₂O₄^2- ==> 2CO₂ .. balanced for C and O

C₂O₄^2- ==> 2CO₂ + 2e- .. balanced for C, O and charge .. balanced oxidation reaction

Multiply reduction rxn by 2 and oxidation rxn by 3 to balance electrons:

2MnO₄^-+ 8H₂O + 6e- ==> 2MnO₂ + 4H₂O + 8OH^-

3C₂O₄^2- ==> 6CO₂ + 6e-

Add together and combine/cancel like terms to obtain final balanced equation:

2MnO₄^-+ 8H₂O + 6e- + 3Cr₂O₄^2- ==> 2MnO₂ + 4H₂O + 8OH^- + 6CO₂ + 6e-

2MnO₄^-+ 4H₂O + 3C₂O₄^2- ==> 2MnO₂ + 8OH^- + 6CO₂ .. balanced redox