October 25, 2012
Example: Metal/Ion Voltaic Cell
V
Co(s)
Zn(s)
Co2+
SO 24
Zn2+
SO 24
Example: A voltaic cell with an inert
electrode
October 25, 2012
Example
Label the cathode, anode, electron movement, ion movement, and write the half
reactions taking place at each half cell. Describe one observation that could be
made at each half cell that would indicate the cell is functioning.
October 25, 2012
Draw a diagram of the following cell
C
|I
|| Pb2+
| Pb
(s) 2(aq), I (aq)
(aq)
(s)
October 25, 2012
October 25, 2012
Calculating Cell Voltage (cell potential)
Ecell = ER -ER
cathode
anode
October 25, 2012
Example #1
What is the cell potential of a voltaic cell that is composed of a
copper half cell and a zinc half cell?
+ 1.10 V
Zn(s) Zn2+(aq)
chromium-tin
E º = +0.77 V
Cu2+(aq) Cu(s)
Eº=?
October 25, 2012
nickel-cobalt
E º = +0.02 V
Voltaic Cell Lab Procedure
Procedure:
1) Get a card from a teacher that identifies one of the six voltaic cells
2) Construct the voltaic cell using a porous cup and a beaker (it does not matter which
half cell goes in which)
3) Measure and record the voltage of your cell
4) Disconnect the leads from the cell, but leave it with the card for your classmates to use
5) Find the other five voltaic cells and record the voltage
6) At the end, clean up the cell you made. Metals are returned, solution go in the waste
container provided