Determination of an Electrochemical Series
In electrochemistry, a voltaic cell is a specially prepared system in which an oxidation-reduction reaction occurs spontaneously. This spontaneous reaction produces an easily measured electrical potential which has a positive value. Voltaic cells have a variety of uses and you commonly refer to them as a “battery”. Half-cells are normally produced by placing a piece of metal into a solution containing a cation of the metal (e.g., Cu metal in a solution of a soluble salt that releases Cu2+ or Cu+ into solution). In this micro-version of a voltaic cell, the half cell will be a small piece of metal placed into three drops of a solution on a piece of filter paper. The solution contains a cation of
Metal M1 (copper) will be assigned an arbitrary value of 0.00 V since it is used as a reference electrode. 9. Using the voltmeter, measure the potential of the remaining possible spontaneous cell combinations. If the sodium or potassium nitrate solution has dried (or if any of the other solutions have dried), you may have to re-moisten it. Record each measured spontaneous cell potential in Data Table 3 and identify which metal was the cathode and the anode for the spontaneous cell. 10. Calculate the predicted potentials for the remaining possible spontaneous cell combinations and record each calculated potential in DATA TABLE 3. Show your calculations within the data table. 11. When you have finished collecting data, use forceps to remove each of the pieces of metal from the filter paper. Rinse each piece of metal with tap water. Dry it and return it to the correct container. Remove the filter paper from the Petri dish using forceps and discard it in the trash. Rinse the Petri dish with tap water, making sure that you do not touch the chemicals.

Adapted from Advanced Chemistry with Vernier & Laboratory Experiments for Advanced Placement Chemistry by Sally Ann Vonderbrink, Ph. D.

Determination of an Electrochemical Series

DATA TABLE 1
Voltaic Cell (metals used) Measured Oxidation Potential, E°ox (V)

DATA TABLE 2
Metal (Mx) Measured E°red, arranged from most positive to