1. Balance Redox Rxns: Fe(OH) 3 + [Cr(OH) 4 ] -1 Fe(OH) 2 + CrO 4 -2 in base

2. Electro- chemistry

3. Metallic Conduction The flow of electrons through a metal

4. Ionic Conduction The movement of ions (electrolytes) through a solution Electrolytic Conduct.

5. Electrode The surface or point in which oxidation or reduction takes place

6. Anode The electrode where oxidation takes place An Ox (-)

7. Cathode The electrode where reduction takes place Red Cat (+)

8. Voltaic or Galvanic Cell Electrochemical Cell in which:

9. a spontaneous oxidation-reduction reaction produces electrical energy

10. Half-Cell A cell where only oxidation or only reduction takes place

11. An electrochemical cell must have two half-cells connected by a salt bridge

12. A half-cell will not work by itself Both half-cells are required

13. Salt Bridge 1) Allows electrical contact between the two half-cells

14. 2) Prevents mixing of the two half- cell solutions

15. 3) Allows ions to flow maintaining electrical neutrality

16. Determining the Redox Rxn & Voltage of an Electrochemical Cell

17. Identify all molecules & ions (reactants) that exist in the electrolytic cell

18. 1) Determine all possible half- reactions that could occur in the system

19. 2 ) Look up each half-rxn from the Std. Redox Tables

20. 3) Record each half-rxn & its standard voltage

21. 4) Save the oxidation half- rxn that has the highest voltage

22. 5) Save the reduction half- rxn that has the highest voltage

23. 6) Balance the electrons between the two half-rxns

24. 7) Add the two half-rxns to obtain the full electrochemical reaction

25. 7) Add the voltage of each half-rxn to obtain the std. voltage required

26. Voltaic Cell Problems

27. Determine all when a cell with a Cu electrode in CuCl 2(aq) is connected to a cell with a Zn electrode in ZnBr 2(aq)

28. Determine all when a cell with a Fe electrode in FeCl 3(aq) is connected to a cell with a Mn electrode in MnCl 2(aq)

29. Determine all when a cell with a Mg electrode in Mg(NO 3 ) 2(aq) is connected to a cell with a Au electrode in Au(NO 3 ) 3 (aq)

31. Electrolysis Using electricity to force a non- spontaneous electrochemical rxn

32. Electrolytic Cell Chemical cell where electrolysis is being performed

33. How to determine the Redox Rxn & voltage of an Electrolytic Cell

34. Identify all molecules & ions (reactants) that exist in the electrolytic cell

35. 1) Determine all possible half- reactions that could occur in the system

36. 2 ) Look up each half-rxn from the Std. Redox Tables

37. 3) Record each half-rxn & its standard voltage

38. 4) Save the oxidation half- rxn that has the highest voltage

39. 5) Save the reduction half- rxn that has the highest voltage

40. 6) Balance the electrons between the two half-rxns

41. 7) Add the two half-rxns to obtain the full electrochemical reaction

42. 7) Add the voltage of each half-rxn to obtain the std. voltage required

43. Determine the rxn that takes place when 1.5 V is passed through two Pt electrodes in a solution containing MgI 2(aq) & ZnCl 2(aq)

44. Determine the rxn that takes place when 2.5 V is passed through two Pt electrode in a solution of NaCl (aq)

45. Determine the rxn that takes place when electricity is passed through two Pt electrode in molten NaCl

46. Drill: Determine the rxn that takes place when electricity is passed through two Pt electrodes in ZnCl 2(aq)

47. Determine the rxns that take place when 9.65 mA is passed for 2.5 Hrs through two Pt electrodes in a solution containing MnBr 2(aq) & AlF 3(aq)

48. Relating Equations  G o =  H o - T  S o  G o = -RTlnK eq  G o = -nF E o

49. Nernst Equation E = E o - (RT/nF)lnQ for non-standard conditions

50. Determine the voltage of a cell with a silver electrode in 1.0 M AgNO 3 & an iron electrode in 0.10 M Fe(NO 3 ) 2 at 27 o C

51. Determine the voltage of a cell with a silver electrode in 1.0 M AgNO 3 & a zinc electrode in 0.010 M Zn(NO 3 ) 2 at 27 o C

52. Determine the voltage of a cell with a copper electrode in 0.10 M CuNO 3 & a zinc electrode in 1.0 M Zn(NO 3 ) 2 at 27 o C

53. Determine the voltage of a cell with a silver electrode in 0.10 M AgNO 3 & a zinc electrode in 1.0 M Zn(NO 3 ) 2 at 27 o C

54. Electroplating & Electro-purifying

55. Electrolysis During electrolysis, oxidation & degradation would occur at the anode while reduction & electroplating would occur at the cathode

56. Current Formula Current = charge/unit time Amps = coul/sec Amount (mass, volume, moles, etc) can be determined from the charge

57. Calculate the mass of copper plated onto the cathode when a 9.65 mAmp current is applied to a solution of CuSO 4 for 5.0 minutes.

58. Calculate the years required to plate 216 kg onto the cathode when a 96.5 mAmp current is applied to a solution of AgNO 3

59. Calculate the current required to purify 510 kg of aluminum oxide in 5.0 hours

60. Calculate the time required to electroplate 19.7 mg of gold onto a plate by passing 965 mA current through a solution of Au(NO 3 ) 3

61. Calculate the time required to gold plate a 2.0 mm layer onto a 250 cm 2 plate by passing 965 mA current through a solution of Au(NO 3 ) 3 (D Au = 20 g/cm 3 )

62. Calculate the time required to purify a 204 kg of ore that is 60.0 % Al 2 O 3 by applying a 965 kA current through molten ore sample:

63. Calculate the time required to purify a 32 kg of ore that is 75.0 % Fe 2 O 3 by applying a 9.65 kA current through molten ore sample:

64. Determine the voltage of a cell with a silver electrode in 5.0 M AgNO 3 & an zinc electrode in 0.25 M Zn(NO 3 ) 2 at 27 o C