1. Standard Cells & Cell Potential

2. Standard Cells
Standard cell: Galvanic cell at SATP with 1.0 mol/L solutions
Standard cell potential (∆E˚): Maximum electric potential difference of a standard cell
Standard reduction potential (∆Er˚): Ability of a standard half-cell to attract electrons in a reduction half-reaction
∆E˚ = ∆Er˚ - ∆Er˚
cell cathode anode
By convention, hydrogen is chosen as a reference half-cell and is assigned a ∆Er˚ of 0 to be used to determine ∆Er˚ of all other half-cells

3. Calculating Cell Potentials
Although you might multiply the half-reactions by a coefficient to balance the electrons, do NOT multiply the ∆Er˚ value
∆E˚ > 0 indicates a spontaneous reaction, a requirement of galvanic cells
E.g. Determine the standard cell potential for a galvanic cell in which the following reaction occurs:
Zn(s) + 2AgNO3(aq)  Zn(NO3)2(aq) + 2Ag(s)

4. Electrolytic Cells ∆E˚ < 0, nonspontaneous
Requires an external battery or power source
Electrolysis is the process of supplying electrical energy for a nonspontaneous reaction to occur
Some applications: Rechargeable batteries, production of elements, electroplating

5. Practice p. 708 #10-12 p. 709 # 2, 6-8 Review: p. 725 # 1-7, 10-14