Redox Reactions: Mno4^- C2O4^2- Method

In this redox reaction, Mno4^- is reduced to Mn^2+ and C2O4^2- is oxidized to CO2. The ion-electron method is used to balance the equation in acidic medium.

Step 1: Write the equation and assign oxidation states

Mno4^- + C2O4^2- → Mn^2+ + CO2

Oxidation states:
Mn: +7 → +2
C: +3 → +4

Step 2: Separate the half-reactions

Oxidation half-reaction: C2O4^2- → CO2
Reduction half-reaction: Mno4^- → Mn^2+

Step 3: Balance the atoms and charges in each half-reaction

Oxidation half-reaction: C2O4^2- → 2CO2 + 2e^-
Reduction half-reaction: 8H+ + Mno4^- + 5e^- → Mn^2+ + 4H2O

Step 4: Balance the electrons by multiplying the half-reactions

Oxidation half-reaction: 5C2O4^2- + 10H2O → 10CO2 + 10e^-
Reduction half-reaction: 16H+ + 2Mno4^- + 10e^- → 2Mn^2+ + 8H2O

Step 5: Add the half-reactions and simplify

5C2O4^2- + 2Mno4^- + 16H+ → 10CO2 + 2Mn^2+ + 8H2O

The balanced equation is now complete.

Conclusion

In the ion-electron method, oxidation and reduction half-reactions are balanced separately and then combined to get a balanced overall equation. This method is useful in acidic or basic solutions, as the half-reactions can be adjusted accordingly. By following the steps above, we were able to balance the redox reaction between Mno4^- and C2O4^2- in acidic medium and determine the products as Mn^2+ and CO2.