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

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. Voltaic or Galvanic Cell Batteries are made up of VCs

11. Half-Cell A cell where either oxidation or reduction takes place

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

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

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

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

16. 3) Allows ions to flow maintaining electrical neutrality

17. Draw a Voltaic Cell made up of two half-cells

18. Drill: Define Each Oxidation Reduction Anode Cathode

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

20. 1) List all species (molecules, elements, & ions) (reactants) that exist in each cell

21. 2a) From the Redox Tables write all possible half- reactions that could occur in the system

22. 2b ) Record the voltage for each half-rxn. If rxn is reversed, change sign.

23. 3) Label the oxidation half- rxn that has the highest voltage

24. 4) Label the reduction half- rxn that has the highest voltage

25. 5) Balance the electrons between the two half-rxns

26. 6a) Add the two half-rxns to obtain the full electrochemical reaction

27. 6b) Add the voltage of each half-rxn to obtain the std. voltage required

28. Determine E o Zn (s) + 2 Ag +1 (aq) 2 Ag (s) + Zn +2 (aq)

29. REDOX Shorthand Zn|Zn +2 ||Ag +1 |Ag ox red Zn||Zn|Zn +2 ||Ag +1 |Ag||Ag an ox red cat

30. Drill: Determine Shorthand Rxn & voltage when Cu +1 is reacts with solid potassium

31. Voltaic Cell Problems

32. 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)

33. Drill: Determine all species that could react when a cell with an Fe electrode in FeCl 3(aq) is connected to a cell with a Mn electrode in MnCl 2(aq)

34. 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)

35. Drill: Determine all species that could react when a cell with an Fe electrode in FeCl 2(aq) is connected to a cell with a Mg electrode in MgCl 2(aq)

36. Determine all when a cell with a Mg electrode in MgCl 2(aq) is connected to a cell with a Au electrode in AuCl 3(aq)

37. Determine all when a cell with a Cd electrode in CdCl 2(aq) is connected to a cell with a Cu electrode in CuI (aq)

38. What could happen if you dissolve AuCl 3 in water?

39. Drill: A voltaic cell is made up of a iron electrode in an aqueous of FeI 2 in one chamber & a copper electrode in an aqueous CuBr 2. Determine all of the substances that could be reactants in this system.

40. A voltaic cell is made up of a iron electrode in an aqueous of FeI 2 in one chamber & a copper electrode in an aqueous CuBr 2. Determine all in this system.

41. Drill: Determine all species that could react when a cell with an Cr electrode in CrBr 3(aq) is connected to a cell with a Sn electrode in SnI 2(aq)

42. Determine all when a cell with an chromium electrode in CrBr 3(aq) is connected to a cell with a tin electrode in SnI 2(aq)

43. Using the standard Reduction Potential Table, determine the element that is the strongest reducing agent, & the one that ic the strongest oxidizing agent.

44. Balance Redox Rxn: SnO 2 + S 8 SnO + SO 2 in acid

45. Balance Redox Rxn: N 2 O 3 + K 2 CrO 4 KNO 3 + Cr +3 in base

46. Balance Redox Rxn: SO + H 2 Cr 2 O 7 H 2 SO 4 + Cr +2

47. Drill: What is the best reducing agent and the best oxidizing agent on the chart?

48. Extremely Important Electrochemical Reactions

49. Lead Sulfate Battery Pb + SO 4 -2  PbSO 4 + 2e - E o = 1.7 V PbO 2 + 4H + + 2e -  PbSO 4 + H 2 O E o = 0.3 V Pb + PbO 2 + 4H + SO 4 -2  2 PbSO 4 + H 2 O E o = 2.0 V

50. Iron Rusting 2Fe  2Fe +2 + 4e - O 2 + 2H 2 O + 4e -  4OH - 2Fe + O 2 + 2H 2 O  2Fe +2 + 4OH -

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

52. Determine rxn, E o,  G o, & K eq for a voltaic cell with half- cells containing Ni (s) in NiCl 2(aq) & Sn (s) in SnCl 2(aq).

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

54. Determine the voltage of a cell with a silver electrode in 1.0 M AgNO 3 & a zinc electrode in 0.010 M ZnCl 2 at 27 o C

55. Drill: Determine the voltage of a cell with an aluminum electrode in 1.0 M AlCl 3 & a zinc electrode in 0.010 M ZnCl 2 at 27 o C

56. Determine the voltage of a cell with an calcium electrode in 1.0 M CaCl 2 & a silver electrode in 0.010 M AgBr at 27 o C

57. Typical Dry Cell Battery

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

59. Electrolytic Cell Chemical cell where electrolysis is being performed

60. How to determine everything in an electrolytic cell

61. 1) List all species (molecules, elements, & ions) (reactants) that exist in each cell

62. 2a) From the Redox Tables write all possible half- reactions that could occur in the system

63. 2b ) Record the voltage for each half-rxn. If rxn is reversed, change sign.

64. 3) Label the oxidation half- rxn that has the highest voltage

65. 4) Label the reduction half- rxn that has the highest voltage

66. 5) Balance the electrons between the two half-rxns

67. 6a) Add the two half-rxns to obtain the full electrochemical reaction

68. 6b) Add the voltage of each half-rxn to obtain the std. voltage required

69. 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)

70. Determine the rxn that takes place when 4.0 V is passed through two Pt electrode in a solution of NaCl (aq)

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

72. Drill: Determine all species that could react when electricity is passed through two Pt electrode in a solution containing CaCl 2(aq) & FeF 2(aq)

73. More Electrolytic Problems

74. Determine the rxns that take place when 2.0 V of electricity is passed through two Pt electrode in a solution containing CaCl 2(aq) & FeF 2(aq)

75. Determine the rxns that takes place when 1.8 V of electricity is passed through two Pt electrodes in ZnCl 2(aq)

76. Determine the rxns that takes place when 2.0 V of electricity is passed through two Pt electrodes in ZnCl 2(aq)

77. Determine the voltage of a cell with a silver electrode in 1.0 M AgNO 3 & an iron electrode in 0.10 M FeCl 2 at 27 o C

78. Drill: Determine all species that could react when electricity is passed through two Pt electrode in a solution containing CaCl 2(aq) & MgF 2(aq)

79. Determine all the reactions that take place when electricity is passed through two Pt electrode in a solution containing CaCl 2(aq) & MgF 2(aq)

80. Electroplating & Electro-purifying

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

82. Power Supply Anode Cathode Impure Metal Pure Metal Metal salt solution

83. Standard Unit of Electricity Amphere (A) 1 Amp = 1 coulomb/sec

84. Unit of Electric Charge Coulomb (C) The amount of any electroplating can be determined from coulombs because the charge of an electron is known

85. Faraday’s Constant The charge of 1 mole of electrons ~96500 C

86. Electroplating Formula Charge = current x time Mass can be determined from the charge

87. Determine the mass of copper plated onto the cathode when 9.65 mA is passed for 2.5 Hrs through two Cu electrodes in a solution containing CuCl 2(aq)

88. Determine the voltage of a cell with a copper electrode in 0.10 M CuI & a zinc electrode in 1.0 M ZnCl 2 at 27 o C

89. Determine the voltage of a cell with a silver electrode in 0.10 M AgNO 3 & a zinc electrode in 1.0 M ZnCl 2 at 27 o C

90. The test on electrochemistry will be on ____day.

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

92. 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.

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

94. Drill: Calculate the current required to purify 510 kg of aluminum oxide in 5.0 hours

95. Balance the Rxn KMnO 4 + HCl MnO 2 + KClO 2

96. 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

97. Determine the voltage of a cell with a silver electrode in 5.0 M AgNO 3 & an zinc electrode in 0.25 M ZnCl 2 at 27 o C

98. Determine the rxn that takes place when 1.0 V is passed through two Pt electrodes in a soln containing NaI (aq) & CoCl 2(aq).

99. 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:

100. Drill: Aluminum ore is purified by electrolysis. Calculate the time required to purify a 51 kg of ore that is 75.0 % Al 2 O 3 by applying a 9.65 kA current through molten ore sample:

101. Calculate the time required to gold plate a 0.20 mm layer onto a plate (SA = 750 cm 2 ) by passing 965 mA current through a solution of AuCl 3 (D Au = 20 g/cm 3 )

102. Current, Mass, Time Formula: Saul’s Rule nFm = MWIt

103. A voltaic cell with a silver electrode in 0.10 M Ag + & a zinc electrode in 1.0 M Zn +2 at 27 o C is allowed to react for 5.0 mins at 9.65 A. Calculate: E o, E,  G o, & mass increase of the cathode.

104. A voltaic cell with a gold electrode in 0.0010 M Au +3 & a zinc electrode in 10.0 M Zn +2 at 27 o C is allowed to react for 5.0 hrs at 9.65 A. Calculate: E o, E,  G o, & mass increase of the cathode.