Balance Redox Rxns:

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

2. AP CHM HW • Read: Chapter 18

3. Review the Multiple-Choice Section of the Midterm.

4. Electro-chemistry

5. Metallic Conduction • The flow of electrons through a metal

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

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

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

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

10. Voltaic or Galvanic Cell • Electrochemical Cell in which:

11. a spontaneous oxidation-reduction reaction produces electrical energy

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

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

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

15. Salt Bridge • ) Allows electrical contact between the two half-cells

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

17. ) Allows ions to flow maintaining electrical neutrality

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

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

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

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

22. ) Record each half-rxn & its standard voltage

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

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

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

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

27. ) 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. AP CHM HW • Read: Chapter 18 • Problems: 7 & 15a • Page: 526

30. REDOX Shorthand • Zn|Zn+2||Ag+1|Ag ox red • Zn||Zn|Zn+2||Ag+1|Ag||Pt an ox red cat

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

32. Voltaic Cell Problems

33. Determine all when a cell with a Cu electrode in CuCl2(aq) is connected to a cell with a Zn electrode in ZnBr2(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. Determine all when a cell with a Mg electrode in MgCl2(aq) is connected to a cell with a Au electrode in AuCl3(aq)

36. Drill: What is the best reducing agent on the chart?

37. Electrolysis • Using electricity to force an, oh fooey, non-spontaneous electrochemical rxn

38. Electrolytic Cell • Chemical cell where electrolysis is being performed

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

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

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

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

43. ) Record each half-rxn & its standard voltage

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

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

46. ) Balance the electrons between the two half-rxns

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

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

49. Determine the rxn that takes place when 1.5 V is passed through two Pt electrodes in a solution containing MgI2(aq) & ZnCl2(aq)

50. AP CHM HW • Read: Chapter 18 • Problems: 23 • Page: 527