Metals can spontaneously plate onto other more active metals in a simple aqueous displacement process but the results are typically not attractive unless the process is very slow (dilute solutions) and adherence of the coating is often poor. That is why almost all practical plating is done in electrolytic cells.

In the lab we looked at the third category: electrolyzing aqueous solutions. In many ways this is the most complicated because in addition to whatever ions might be present in the mixture there is always water as a possible target for reduction or oxidation. Electrolysis of aqueous solutions therefore frequently involves competition processes. The rule is: the oxidation and reduction with potentials closer to 0.00 V are the ones which generally occur.

In order to further simplify our initial discussion of the processes involved we looked at cells in which the electrodes themselves were inert, i.e., they could not be oxidized or reduced. With that in mind, we might look at the first system, the electrolysis of NaF solution.