Which of the following is a balanced chemical equation?

H2O2 → H2O + O2

SO2 + O2 + 2 H2O → 4 H2SO4

2 Fe2O3 + 3 C → 4 Fe + 3 CO2

2 Mg + HC1 → MgCl2 + H2

1. Not the first option because there are too many Oxygen molcecules on the right. (2O: 3O)

2. Not the second option because, again the oxygen's are not balanced. (6O:8O)

3. Correct! this is a balanced equation as there are equal amounts of all the molecules on each side of the reaction.

4. Not the fourth one because the Magnesium (Mg) are not balanced. (2Mg:1Mg)

Any Questions?