1. Schedule Today (4/12): Chapter 11 Monday (4/15): Chapter 21
Any questions?
Monday (4/15): Chapter 21
Start reading Chapter 21 – through at least through Section 21.2
No office hours Monday, April 15

2. Electroplating
Get silver metal from dissolved silver ions. To reduce silver ions, an oxidation must occur. Ag+ + e–  Ag (0.80 V)

3. Clicker Question
Electrolysis of a molten salt with the formula MCl, using a current of 3.86 amp for 16.2 min, deposits 1.52 g of metal. Identify the metal. a) Li b) Na c) K d) Rb e) Ca

4. Electrolysis of Water
Consider the electrolysis of water in which we run a current through water to carry out the following reaction: H2O  H2 + ½O2 To run a current through water we need an electrolyte. Let’s consider NaCl, HCl, and NaOH. Does the choice of electrolyte affect the voltage needed to cause this reaction? If so, how. If not, why not?

5. Electrolysis of Water
Assume we run a current through a 1M solution of NaCl. Thus, we have H2O, 1M Na+, and 1M Cl–. Use the relevant reduction potentials to determine the reduction half-reaction and the oxidation half-reaction for the overall reaction that occurred and write each of these (3 reactions). Also determine the minimum voltage required for the reaction at 25°C.

6. Electrolysis of Water
Cl2 + 2e–  2Cl– 1.36 V O2 + 4H+ + 4e–  2H2O 1.23 V O2 + 2H2O + 4e–  4OH– 0.40 V 2H+ + 2e–  H V 2H2O + 2e–  H2 + 2OH– –0.83 V Na+ + e–  Na –2.71 V

7. Electrolysis of Water
Instead of 1.00 M NaCl as the electrolyte, suppose we use 1 M HCl. Thus, we have H2O, 1M H+, and 1M Cl–. Use the relevant standard reduction potentials to determine the reduction half-reaction and the oxidation half-reaction for the overall reaction that occurred and write each of these (3 reactions). Also determine the minimum voltage required for the reaction at 25°C.

8. Electrolysis of Water
Suppose we use 1 M NaOH as the electrolyte. Thus, we have H2O, 1M Na+, and 1M OH–. Use the relevant standard reduction potentials to determine the reduction half-reaction and the oxidation half-reaction for the overall reaction that occurred and write each of these (3 reactions). Also determine the minimum voltage required for the reaction at 25°C.

9. ΔG° and Ɛ°

10. Clicker Question
A concentration cell is constructed using two metal (M) electrodes with M2+ concentrations of 0.10M and 1.00 x 10–5M in the two half-cells. Determine the standard reduction potential of M2+. a) V b) V c) –0.118 V d) 0 V e) It cannot be determined with the information given.