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Balance Redox Rxns:

Balance Redox Rxns:. Fe(OH) 3 + [Cr(OH) 4 ] -1 Fe(OH) 2 + CrO 4 -2. Electro-chemistry. Metallic Conduction. The flow of electrons through a metal. Ionic Conduction. The movement of ions (electrolytes) through a solution Electrolytic Conduct. Electrode.

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Balance Redox Rxns:

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  1. Balance Redox Rxns: • Fe(OH)3 + • [Cr(OH)4]-1 • Fe(OH)2 + CrO4-2

  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 • ) Allows electrical contact between the two half-cells

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

  16. ) 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. b ) 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 Eo 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 CuCl2(aq) is connected to a cell with a Zn electrode in ZnBr2(aq)

  33. Drill: Determine all species that could react when a cell with an Fe electrode in FeCl3(aq) is connected to a cell with a Mn electrode in MnCl2(aq)

  34. Determine all when a cell with a Fe electrode in FeCl3(aq) is connected to a cell with a Mn electrode in MnCl2(aq)

  35. Drill: Determine all species that could react when a cell with an Fe electrode in FeCl2(aq) is connected to a cell with a Mg electrode in MgCl2(aq)

  36. Determine all when a cell with a Mg electrode in MgCl2(aq) is connected to a cell with a Au electrode in AuCl3(aq)

  37. Determine all when a cell with a Cd electrode in CdCl2(aq) is connected to a cell with a Cu electrode in CuI(aq)

  38. What could happen if you dissolve AuCl3 in water?

  39. Drill: A voltaic cell is made up of a iron electrode in an aqueous of FeI2 in one chamber & a copper electrode in an aqueous CuBr2. 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 FeI2 in one chamber & a copper electrode in an aqueous CuBr2. Determine all in this system.

  41. Drill: Determine all species that could react when a cell with an Cr electrode in CrBr3(aq) is connected to a cell with a Sn electrode in SnI2(aq)

  42. Determine all when a cell with an chromium electrode in CrBr3(aq) is connected to a cell with a tin electrode in SnI2(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: • SnO2 + S8 • SnO + SO2 • in acid

  45. Balance Redox Rxn: • N2O3 + K2CrO4 • KNO3 + Cr+3 • in base

  46. Balance Redox Rxn: • SO + H2Cr2O7 • H2SO4 + 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 + SO4-2  PbSO4 + 2e-Eo = 1.7 V PbO2 + 4H+ + 2e- PbSO4 + H2O Eo = 0.3 V Pb + PbO2 + 4H+ SO4-2  2 PbSO4 + H2O Eo = 2.0 V

  50. Iron Rusting 2Fe  2Fe+2 + 4e- O2 + 2H2O + 4e- 4OH- 2Fe + O2 + 2H2O  2Fe+2 + 4OH-

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