1. Galvanic Cells
Assignment # 17.1

2. What is it? o.O
A device in which chemical energy from a spontaneous redox reaction is changed to electrical energy that can be used to do work

3. Parts of a battery…
Salt bridge: a U-tube containing an electrolyte that connects the two compartments of a galvanic cell, allowing ion flow without extensive mixing of the different solutions
Anode: the electrode in a galvanic cell at which oxidation occurs
Cathode: the electrode in a galvanic cell at which reduction occurs

4. REMEMBER…
Oxidation-reduction reaction: involves a transfer of electrons from the reducing agent to the oxidizing agent
Reduction: 8H+ + MnO4- + 5e- → Mn2+ + 4H2O
Oxidation: 5(Fe2+ → Fe3+ + e-)

5. Standard Reduction Potentials
The potential of a half-reaction under standard state conditions, as measured against the potential of the standard hydrogen electrode

6. How to find standard reduction potentials…
1) Break reaction into oxidation and reduction half reactions, label anode & cathode
2) Find the potentials of the half reactions (pg. 843 Table 17.1)
3) Then add potentials together using equation E°cell = E° + E°

7. Ex - 1
Consider a galvanic cell based on the reaction Al3+(aq) + Mg(s) → Al(s) + Mg2+(aq)
Calculate the standard reduction potential (E°)

8. Practice 17.1
P 880 # 26, 28, 29