Understanding Oxidation and Reduction

* Oxidation: Loss of electrons, increase in oxidation number.

* Reduction: Gain of electrons, decrease in oxidation number.

Analyzing the Reaction

1. Assign Oxidation Numbers:

* Reactants:

* H in HCl: +1

* Cl in HCl: -1

* K in KMnO4: +1

* Mn in KMnO4: +7

* O in KMnO4: -2

* H in H2C2O4: +1

* C in H2C2O4: +3

* O in H2C2O4: -2

* Products:

* C in CO2: +4

* O in CO2: -2

* Mn in MnO2: +4

* O in MnO2: -2

* K in KCl: +1

* Cl in KCl: -1

* H in H2O: +1

* O in H2O: -2

2. Identify Changes in Oxidation Numbers:

* Manganese (Mn): Goes from +7 in KMnO4 to +4 in MnO2. This is a decrease in oxidation number, indicating reduction.

* Carbon (C): Goes from +3 in H2C2O4 to +4 in CO2. This is an increase in oxidation number, indicating oxidation.

Conclusion

The element that is reduced in the reaction is Manganese (Mn).