Oxygen and oxygen containing compounds are involved in many different reactions. Which balanced equation represents a reaction that involves 6 atoms of oxygen?
1) 2H2 + O2 → 2H₂O
2) 2H₂O → 2H2 + O2
3) 2CO₂ + 4H₂O → 2C₂H₅OH + 3O2
4) 2C₂H₅OH + 3O2 → 2CO₂ + 4H₂O