1. Lecture 264/6/05

2. Nernst Equation (another way to write it)

3. Problem 20.90 Four metals A, B, C, and D exhibit the following properties Only A and C react with 1.0 M HCl to give H 2 (g) When C is added to solutions of the ions of the other metals, metallic B, D, and A are formed Metal D reduces B n+ to give metallic B and D n+. Based on the information above, arrange the 4 metals in order of increasing ability to act as reducing agents.

4. Nernst Equation and Equilbrium When a cell is at equilibrium, E cell = 0

5. Example Calculate the equilibrium constant for: 2Ag + (aq) + Hg (l) ↔ 2Ag(s) + Hg 2+ (aq) E° (V) Hg 2+ (aq) + 2e -  Hg (l) 0.855 Ag + (aq) + e -  Ag(s)0.7994

6. Concentration cell A cell with an EMF generated solely from a difference in concentration For example what is the cell voltage for a cell with: An anode with a solid Ni electrode in a solution of 0.001 M Ni 2+ A cathode with a solid Ni electrode in a solution 1M Ni 2+

7. Some applications of electrochemistry Batteries Breathalyzer Neurons (concentration cell) pH probe Fuel cell Corrosion Electroplating