1. Redox

2. Solutions of potassium iodide, potassium iodate, and dilute sulfuric acid are mixed.

3. I-(aq) + IO3-(aq) + H+(aq) ® H2O + I2(aq) [or I3-(aq)]

4. Iron (III) ions are reduced by iodide ions

5. Fe I-  Fe I2

6. Potassium permanganate solution is added to concentrated hydrochloric acid

7. MnO4- + H+ + Cl-  Mn 2+ + Cl2 + H2O

8. Magnesium metal is added to dilute nitric acid, giving as one of the products a compound in which the oxidation number for nitrogen is -3

9. Mg + H+ + NO3-  NH4+ + Mg 2+ + H2O

10. A solution of potassium iodide is electrolyzed

11. I- + H2O  I2 + H2 + OH-

12. Potassium dichromate solution is added to an acidified solution of sodium sulfite

13. Cr2O7 2- + H+ + SO3 2-  Cr 3+ + SO4 2- + H2O

14. Solutions of potassium Iodide, potassium iodate, and dilute sulfuric acid are mixed

15. I- + IO H+--> H2O + I2

16. Solutions of tin (II) sulfate is added to a solution of Iron (III) sulfate

17. Sn Fe 3+  Sn Fe 2+

18. Metallic copper is heated with concentrated sulfuric acid

19. Cu + H+ + SO4 2-  Cu 2 + SO2 + H2O

20. Manganese (IV) oxide is added to warm, concentrated hydrobromic acid

21. MnO2 + H+ + Br-  Mn 2+ + Br2 + H2O

22. Chlorine gas is bubbled into dilute sodium hydroxide

23. Cl2 + OH-  ClO- + Cl- + H2O

24. Solid iron (III) oxide is heated in excess carbon monoxide

25. Fe2O3 + CO  Fe CO2

26. Hydrogen peroxide solution is added to acidified potassium iodide solution

27. H2O2 + H+ + I-  H2O + I2

28. Hydrogen peroxide is added to an acidified solution of potassium dichromate

29. H2O2 + H+ + Cr2O7 2- 
Cr H2O + O2

30. Sulfur dioxide gas is bubbled through an acidified solution of potassium permanganate

31. SO2 + H+ + MnO4 - 
Mn H2O + SO4 2-

32. A solution containing tin (II) ions is added to an acidified solution of potassium dichromate

33. Sn H+ + Cr2O7 2- 
Cr H2O + Sn 4+

34. Solid silver sulfide is warmed with dilute nitric acid

35. Ag2S + H+ + NO3- 
S + NO + H2O

36. Pellets of lead are dropped into hot sulfuric acid

37. Pb + H+ + SO4 2- 
H2O + SO2 + Pb 2+ or PbSO4

38. Potassium permanganate solution is added to a solution of oxalic acid, acidified with a few drops of sulfuric acid

39. MnO4- + H+ + H2C2O4  Mn 2+ + H2O + CO2

40. Powdered iron is added to a solution of iron (III) sulfate

41. Fe + Fe 3+  Fe 2+

42. A concentrated solution of hydrochloric acid is added to powdered manganese dioxide and gently heated

43. H+ + Cl- + MnO2  Cl2 + Mn 2+ + H2O

44. A strip of copper metal is added to a concentrated solution of sulfuric acid

45. Cu + H+ + SO4 2-  Cu SO2 + H2O

46. Copper (II) sulfide is oxidized by dilute nitric acid

47. CuS + H + + NO3 - 
Cu NO + H2O + S

48. Hydrogen peroxide solution is added to a solution of iron (II) sulfate

49. H2O2 + Fe 2+  Fe H2O

50. Solid silver is added to a dilute nitric acid (6M) solution

51. Ag + H+ + NO3 -  Ag+ + H2O + NO

52. A solution of formic acid, HCOOH, is oxidized by an acidified solution of potassium dichromate

53. HCOOH + H+ Cr2O7 2- 
Cr H2O + CO2

54. A solution of tin (II) chloride is added to a solution of iron (III) sulfate

55. Sn Fe 3+  Sn Fe 2+