1. 1. What is the oxidation number of oxygen in H2O2?

2. 2. What is the oxidation number of sulfur in Na2S2O3?

3. 3. In 2 KMnO4 + 16 HCl → 2 MnCl2 + 5 Cl2 + 8 H2O, which species contains the element reduced?

4. 4. In the reaction 2 AgNO3 + H2S → Ag2S + 2 HNO3, which species is oxidized?

5. 5. What is the oxidation number of phosphorus in P4?

6. 6. Which reaction is an example of a combination redox reaction?

7. 7. What is the oxidation number of bromine in BrF3?

8. 8. What is the oxidation number of chlorine in KClO3?

9. 9. In 2 Na2S2O3 + O2 → 2 Na2SO4, what is the total number of electrons transferred per mole of Na2S2O3?

10. 10. In 2 Cr(OH)3 + 3 H2O2 + 4 NaOH → 2 Na2CrO4 + 8 H2O, how many electrons are lost per chromium atom?

11. 11. In the reaction 2 FeCl2 + Cl2 → 2 FeCl3, which element is oxidized?

12. 12. In 2 Na2S + 3 O2 → 2 Na2O + 2 SO2, what is the total number of electrons transferred per mole of Na2S?

13. 13. In PbS + 4 H2O2 → PbSO4 + 4 H2O, which species is the reducing agent?

14. 14. What is the oxidation number of chlorine in ClO2?

15. 15. Which of the following is a displacement reaction involving redox?