1. ELECTROCHEMISTRY
Chap 20

2. Nernst Equation for a Complete Reaction
Ecell = E+ − E− = Ecathode − Eanode
Only valid when both ½-rxns written as reductions
Given:
Cd (s) │ Cd(NO3)2 (aq); MA ║ FeCl2 (aq); MC │ Fe (s)
[Cd2+] = M; [Fe2+] = M Ans = −0.058 V
(b) [Cd2+] = M; [Fe2+] = 1.0 M; Ans = V

3. Calculate the cell potential for:
In Class Exercise:
Calculate the cell potential for:
Cu │ CuCl2 ( M) ║ AgNO3 ( M) │ Ag
Ans = V
Calculate the cell potential for:
Pt │ UO22+ ( M); U4+ (0.200 M); H+ ( M ║
Fe2+ ( M); Fe3+ ( M) │ Pt
Ans = V
UO H+ + 2e− → U4+ + 2H2O; Eo = V

4. Applications of Oxidation-Reduction Reactions
Batteries and Fuel Cells
Corrosion
Electrolysis

5. Batteries Fig 20.19 A 12 V automobile Fig 20.19 Combining cells
lead-acid battery
Fig Combining cells

6. Fig 20.21 Cutaway view of a miniature alkaline cell

7. Fig 20.24 Corrosion of iron in contact with water

8. Fig 20.25 Cathodic protection of iron in contact with zinc

9. Fig 20.26 Cathodic protection of an iron water pipe
Figure 20-26
Title:
Cathodic protection of an iron water pipe.
Caption:
A mixture of gypsum, sodium sulfate, and clay surrounds the magnesium anode to promote conductivity of ions. The pipe, in effect, is the cathode of a voltaic cell.
Notes:
Keywords:

10. Fig 20.27 Electrolysis of molten sodium chloride
Figure 20-27
Title:
Electrolysis of molten sodium chloride.
Caption:
Cl– ions are oxidized to Cl2(g) at the anode, and Na+ ions are reduced to Na(l) at the cathode.
Notes:
Keywords: