1. Electrochemistry
Lesson 7
The Standard
Hydrogen Cell

2. The Standard Hydrogen Half Cell
The zero point of the reduction chart is the hydrogen half-cell.
E is the cell potential or voltage
E0 is the standard cell potential
@ 25 oC
solutions are 1.0 M
gases are 101 KPa

3. All half reactions are compared to H2
Ag+ reacts with H2 spontaneously Eo = v
Zn2+ is nonspontaneous with H2 Eo = v
The voltage for any combination is the difference

4. Using the Reduction Potential Chart
Look on your reduction chart to find the voltage of each agent. Oxidizing agents are on the left and reducing agents are on the right. 
Formula Agent Type E0
HClO4 oxidizing

6. Using the Reduction Potential Chart
Look on your reduction chart to find the voltage of each agent. Oxidizing agents are on the left and reducing agents are on the right. 
Formula Agent Type E0
ClO4- Acid oxidizing v
HNO3 oxidizing

7. HNO3 is both
H+ and NO3-
Take higher one
Stronger Oxidizing Agent

8. Using the Reduction Potential Chart
Look on your reduction chart to find the voltage of each agent. Oxidizing agents are on the left and reducing agents are on the right. 
Formula Agent Type E0
ClO4- Acid oxidizing v
HNO3 oxidizing v
HCl oxidizing

10. Using the Reduction Potential Chart
Look on your reduction chart to find the voltage of each agent. Oxidizing agents are on the left and reducing agents are on the right. 
Formula Agent Type E0
ClO4- Acid oxidizing v
HNO3 oxidizing v
HCl oxidizing v
SO reducing

11. Oxidation
The reaction is reversed so the E0 = v

12. Using the Reduction Potential Chart
Look on your reduction chart to find the voltage of each agent. Oxidizing agents are on the left and reducing agents are on the right. 
Formula Agent Type E0
ClO4- Acid oxidizing v
HNO3 oxidizing v
HCl oxidizing v
SO reducing v
MnO4- Acid oxidizing

14. Using the Reduction Potential Chart
Look on your reduction chart to find the voltage of each agent. Oxidizing agents are on the left and reducing agents are on the right.  
Formula Agent Type E0
ClO4- Acid oxidizing v
HNO3 oxidizing v
HCl oxidizing v 
SO reducing v
MnO4- Acid oxidizing v
MnO4- Alkaline oxidizing

16. Using the Reduction Potential Chart
Look on your reduction chart to find the voltage of each agent. Oxidizing agents are on the left and reducing agents are on the right. 
Formula Agent Type E0
ClO4- Acid oxidizing v
HNO3 oxidizing v
HCl oxidizing v
SO reducing v
MnO4- Acid oxidizing v
MnO4- Alkaline oxidizing v

17. Formula Agent Type E0
H2SO4 oxidizing

18. H2SO4 → HSO H+
Don’t have SO42-

19. Formula Agent Type E0
H2SO4 oxidizing v
H2O Neutral oxidizing

21. Formula Agent Type E0 H2SO4 oxidizing 0.00 v
H2O Neutral oxidizing v
H2O Neutral reducing

23. Formula Agent Type E0 H2SO4 oxidizing 0.00 v
H2O Neutral oxidizing v
H2O Neutral reducing v
Fe2+ reducing

24. Formula Agent Type E0 H2SO4 oxidizing 0.00 v
H2O Neutral oxidizing v
H2O Neutral reducing v
Fe2+ reducing v
Fe2+ oxidizing

25. Formula Agent Type E0 H2SO4 oxidizing 0.00 v
H2O Neutral oxidizing v
H2O Neutral reducing v
Fe2+ reducing v
Fe2+ oxidizing v

26. Determine if the reaction below is spontaneous
Determine if the reaction below is spontaneous. Write a balanced equation for the reaction and calculate the E0.
1. MnO4- & Mn2+ Acid

27. The top reaction is written forward
Reduction
Oxidation
The bottom reaction is reversed and the voltage is changed to negative

28. Determine if the reaction below is spontaneous
Determine if the reaction below is spontaneous. Write a balanced equation for the reaction and calculate the E0.
1. MnO4- & Mn2+ Acid
2(MnO H e-→ Mn H2O) v
5(Mn H2O → MnO2(s)+ 4H e-) v
2MnO4-+16H++5Mn2++10H2O → 2Mn2++8H2O+5MnO2(s)+20H+
2MnO Mn H2O → 5MnO2(s) H v
simplify
add potentials 3 2 4
0.29 v
positive voltage- spontaneous