2. Electrolysis Electrolysis describes what happens in an electrolytic cell and means to use electricity to make chemicals. Pb Al Zn Na K Li H 2 Cl 2 F 2 I 2 O 2 are all made by electrolysis When metals are made by electrolysis it is sometimes called electrowinning as the metal is won from the ion as it is reduced. Pb 2+ + 2e - → Pb (s) 2Cl - → Cl 2(g) + 2e -

3. Electrolysis of AluminumAlcanKitimat B.C. Name of the Ore used: Bauxite Al 2 O 3. 3H 2 O Heating drives off the water Al 2 O 3. 3H 2 O + Heat →Al 2 O 3 +3H 2 O Melting point of Bauxite is 2045 0 C This is too hot! Cryolite is added Lowers the melting point to 1000 0 C

4. DC Power - + Al 2 O 3(l) CC

5. DC Power - + Al 2 O 3(l) CC Al 3+ O 2-

6. DC Power - + Al 2 O 3(l) CC Al 3+ O 2- - reduction

7. DC Power - + Al 2 O 3(l) CC Al 3+ O 2- - Reduction + Oxidation

8. DC Power - + Al 2 O 3(l) CC Al 3+ O 2- - Reduction Cathode + Oxidation Anode

9. DC Power - + Al 2 O 3(l) CC Al 3+ O 2- - Reduction Cathode + Oxidation Anode

10. DC Power - + Al 2 O 3(l) CC Al 3+ O 2- - Reduction Cathode Al 3+ + 3e - → Al (s) + Oxidation Anode

11. DC Power - + Al 2 O 3(l) CC Al 3+ O 2- - Reduction Cathode Al 3+ + 3e - → Al (s) + Oxidation Anode 2O 2- → O 2 + 4e -

12. DC Power - + Al 2 O 3(l) CC Al 3+ O 2- - Reduction Cathode Al 3+ + 3e - → Al (s) + Oxidation Anode 2O 2- → O 2 + 4e - Liquid Al floats to the top and is removed.

13. DC Power - + Al 2 O 3(l) CC Al 3+ O 2- - Reduction Cathode Al 3+ + 3e - → Al (s) + Oxidation Anode 2O 2- → O 2 + 4e - Liquid Al floats to the top and is removed. Oxygen gas

14. Non-Inert Electrodes You must understand that a non-inert Anode might oxidize. K 2 SO 4(aq) DC Power - + Cu

15. Non-Inert Electrodes You must understand that a non-inert Anode might oxidize. The Cathode will stay inert because it already is reduced. K 2 SO 4(aq) DC Power - + Cu

16. Non-Inert Electrodes You must understand that a non-inert Anode might oxidize. The Cathode will stay inert because it already is reduced. DC Power - + K 2 SO 4(aq) Cu 2K + SO 4 2- H 2 O

17. Non-Inert Electrodes You must understand that a non-inert Anode might oxidize. The Cathode will stay inert because it already is reduced. DC Power - + K 2 SO 4(aq) Cu 2K + SO 4 2- H 2 O - Cathode Reduction

18. Non-Inert Electrodes You must understand that a non-inert Anode might oxidize. The Cathode will stay inert because it already is reduced. DC Power - + K 2 SO 4(aq) Cu - Cathode Reduction 2H 2 O + 2e - → H 2 +2OH - -0.41 v 2K + SO 4 2- H 2 O

19. Non-Inert Electrodes You must understand that a non-inert Anode might oxidize. The Cathode will stay inert because it already is reduced. DC Power - + K 2 SO 4(aq) Cu - Cathode Reduction 2H 2 O + 2e - → H 2 +2OH - -0.41 v + Anode Oxidation 2K + SO 4 2- H 2 O

20. You must look at the possible oxidation of: H2OH2O SO 4 2- Cu Check out the reduction chart! S 2 O 8 2- + 2e - →2SO 4 2- 2.01 v 1/2O 2 + 2H + (10 -7 M) → H 2 0 0.82 v Cu + + 1e - → Cu (s) 0.52 v Cu 2+ + 2e - → Cu (s) *0.34 v * Strongest Reducing Agent

21. Non-Inert Electrodes You must understand that a non-inert Anode might oxidize. The Cathode will stay inert because it already is reduced. DC Power - + K 2 SO 4(aq) Cu 2K + SO 4 2- - Cathode Reduction 2H 2 O + 2e - → H 2 +2OH - -0.41 v + Anode Oxidation Cu (s) → Cu 2+ +2e - -0.34 v

22. Non-Inert Electrodes You must understand that a non-inert Anode might oxidize. The Cathode will stay inert because it already is reduced. DC Power - + K 2 SO 4(aq) Cu 2K + SO 4 2- - Cathode Reduction 2H 2 O +2e → H 2(g) +2OH - -0.41 v + Anode Oxidation Cu (s) → Cu 2+ +2e - -0.34 v 2H 2 O + Cu (s) → Cu 2+ + H 2 +2OH - E 0 = -0.75 v MTV = +0.75 v

23. HCl (aq) ZnCu 0.76 v Voltmeter Analyze This Cell

24. HCl (aq) ZnCu 0.76 v Voltmeter Analyze This Cell Pourous membrane Or it might look like this

25. HCl (aq) ZnCu 0.76 v Voltmeter Analyze This Cell H + H 2 O Cl -

26. HCl (aq) ZnCu 0.76 v Voltmeter Analyze This Cell H + H 2 O Cl - Is this cell electrolytic or electrochemical?

27. HCl (aq) ZnCu 0.76 v Voltmeter Analyze This Cell H + H 2 O Cl - Electrochemical- There is no power supply Cu is higher and the cathode Zn is lower and the anode.

28. HCl (aq) ZnCu 0.76 v Voltmeter Analyze This Cell H + H 2 O Cl - Electrochemical- Cu is higher and the cathode Zn is lower and the anode. Cathode Reduction No Cu 2+ to reduce!

29. HCl (aq) ZnCu 0.76 v Voltmeter Analyze This Cell H + H 2 O Cl - Electrochemical- Cu is higher and the cathode Zn is lower and the anode. Cathode Reduction 2H + + 2e - → H 2(g) 0.00 v

30. HCl (aq) ZnCu 0.76 v Voltmeter Analyze This Cell H + H 2 O Cl - Electrochemical- Cu is higher and the cathode Zn is lower and the anode. Cathode Reduction 2H + + 2e - → H 2(g) 0.00 v Anode Oxidation What oxidizes? Zn H 2 O Cl -

31. HCl (aq) ZnCu 0.76 v Voltmeter Analyze This Cell H + H 2 O Cl - Electrochemical- Cu is higher and the cathode Zn is lower and the anode. Cathode Reduction 2H + + 2e - → H 2(g) 0.00 v Anode Oxidation Zn → Zn 2+ + 2e - 0.76 v

32. HCl (aq) ZnCu 0.76 v Voltmeter Analyze This Cell H + H 2 O Cl - 2H + + Zn (s) → Zn 2+ + H 2(g) E 0 = 0.76 v Cathode Reduction 2H + + 2e - → H 2(g) 0.00 v Anode Oxidation Zn (s) → Zn 2+ + 2e - 0.76 v

33. Electroplating Electroplating is the process of reducing a metal on to the surface of another. Anode:Metal to be plated on top the other metal Cathode:The other metal to be covered with the new metal Electrolyte:Must contain the ion of the metal that plates Ni plating a Cu penny Anode: Cathode: Electrolyte: DC Power

34. Electroplating Electroplating is the process of reducing a metal on to the surface of another. Anode:Metal to be plated on top the other metal Cathode:The other metal to be covered with the new metal Electrolyte:Must contain the ion of the metal that plates Ni plating a Cu penny Anode:Ni Cathode: Electrolyte: DC Power Ni

35. Electroplating Electroplating is the process of reducing a metal on to the surface of another. Anode:Metal to be plated on top the other metal Cathode:The other metal to be covered with the new metal Electrolyte:Must contain the ion of the metal that plates Ni plating a Cu penny Anode:Ni Cathode:Cu Electrolyte: DC Power CuCu Ni

36. Electroplating Electroplating is the process of reducing a metal on to the surface of another. Anode:Metal to be plated on top the other metal Cathode:The other metal to be covered with the new metal Electrolyte:Must contain the ion of the metal that plates Ni plating a Cu penny Anode:Ni Cathode:Cu Electrolyte:Ni(NO 3 ) 2 DC Power CuCu Ni Ni 2+ NO 3 -

37. Electroplating Electroplating is the process of reducing a metal on to the surface of another. Anode:Metal to be plated on top the other metal Cathode:The other metal to be covered with the new metal Electrolyte:Must contain the ion of the metal that plates Ni plating a Cu penny Anode:Ni Cathode:Cu Electrolyte:Ni(NO 3 ) 2 DC Power - + CuCu Ni Ni 2+ NO 3 -

38. Electroplating Electroplating is the process of reducing a metal on to the surface of another. Anode:Metal to be plated on top the other metal Cathode:The other metal to be covered with the new metal Electrolyte:Must contain the ion of the metal that plates Ni plating a Cu penny Anode:Ni Cathode:Cu Electrolyte:Ni(NO 3 ) 2 DC Power - + CuCu Ni Ni 2+ NO 3 - - Reduction Cathode

39. Electroplating Electroplating is the process of reducing a metal on to the surface of another. Anode:Metal to be plated on top the other metal Cathode:The other metal to be covered with the new metal Must be negative! Electrolyte:Must contain the ion of the metal that plates Ni plating a Cu penny Anode:Ni Cathode:Cu Electrolyte:Ni(NO 3 ) 2 DC Power - + CuCu Ni Ni 2+ NO 3 - - Reduction Cathode Ni 2+ + 2e - → Ni (s)

40. Electroplating Electroplating is the process of reducing a metal on to the surface of another. Anode:Metal to be plated on top the other metal Cathode:The other metal to be covered with the new metal Electrolyte:Must contain the ion of the metal that plates Ni plating a Cu penny Anode:Ni Cathode:Cu Electrolyte:Ni(NO 3 ) 2 DC Power - + CuCu Ni Ni 2+ NO 3 - - Reduction Cathode Ni 2+ + 2e - → Ni (s) + Oxidation Anode Ni (s) → Ni 2+ + 2e - e-e-

41. Silver plating a Loonie Anode: Cathode: Electrolyte: DC Power $1$1

42. Silver plating a Loonie Anode:Ag Cathode: Electrolyte: DC Power $1$1 Ag

43. Silver plating a Loonie Anode:Ag Cathode:Loonie Electrolyte: DC Power - + $1$1 Ag Loonie

44. Silver plating a Loonie Anode:Ag Cathode:Loonie Electrolyte: AgNO 3 DC Power - + $1$1 Ag Loonie Ag + NO 3 -

45. Silver plating a Loonie Anode:Ag Cathode:Loonie Electrolyte: AgNO 3 DC Power - + $1$1 Ag Loonie Ag + NO 3 - - Reduction Cathode Ag + + 1e - → Ag (s) + Oxidation Anode Ag (s) → Ag + + 1e - e-e- e-e-

46. Electrorefining Electrorefining is the process of purifying a metal by electrolysis. Impure metal is oxidized at the anode and pure metal is reduced at the cathode. This is the same as electroplating. The Electrorefinning of LeadCominco Trail, B.C. Cathode: Anode: Electrolyte: DC Power - +

47. Electrorefining Electrorefining is the process of purifying a metal by electrolysis. Impure metal is oxidized at the anode and pure metal is reduced at the cathode. This is the same as electroplating. The Electrorefinning of LeadCominco Trail, B.C. Cathode: Pure Pb Anode: Electrolyte: DC Power - +

48. Electrorefining Electrorefining is the process of purifying a metal by electrolysis. Impure metal is oxidized at the anode and pure metal is reduced at the cathode. This is the same as electroplating. The Electrorefinning of LeadCominco Trail, B.C. Cathode: Pure Pb Anode: Impure Pb Electrolyte: DC Power - +

49. Electrorefining Electrorefining is the process of purifying a metal by electrolysis. Impure metal is oxidized at the anode and pure metal is reduced at the cathode. This is the same as electroplating. The Electrorefinning of LeadCominco Trail, B.C. Cathode: Pure Pb Anode: Impure Pb Electrolyte: Pb(NO 3 ) 2 DC Power - + Pb 2+ NO 3 -

50. Electrorefining Electrorefining is the process of purifying a metal by electrolysis. Impure metal is oxidized at the anode and pure metal is reduced at the cathode. This is the same as electroplating. The Electrorefinning of LeadCominco Trail, B.C. Cathode: Pure Pb Anode: Impure Pb Electrolyte: Pb(NO 3 ) 2 DC Power - + Pb 2+ NO 3 - - Reduction Cathode Pb 2+ + 2e - → Pb (s )

51. Electrorefining Electrorefining is the process of purifying a metal by electrolysis. Impure metal is oxidized at the anode and pure metal is reduced at the cathode. This is the same as electroplating. The Electrorefinning of LeadCominco Trail, B.C. Cathode: Pure Pb Anode: Impure Pb Electrolyte: Pb(NO 3 ) 2 DC Power - + Zn 2+ Pb 2+ NO 3 - - Reduction Cathode Pb 2+ + 2e - → Pb (s ) + Oxidation Anode Pb (s) → Pb 2+ + 2e - Au Cu