- the electrolysis of molten salts
- the electrolysis of aqueous solutions
Of the three, perhaps the first is the simplest. Molten salts generally contain cations and anions which can be reduced or oxidized to elements. An example is sodium chloride.
Mixtures of salts are sometimes electrolyzed to lower the melting point of the mixture.
Electroplating is a process of covering one metal (or other conductive object) with another. Generally the metal that is to be plated is the anode in the cell (since the anode will be oxidized and dissolve into the mixture). The ions of the metal are then reduced at the cathode to cover it. Plating can take place in either aqueous solution or in molten salt baths. In aqueous solutions there can be problems with competition processes such as the electrolysis of the water itself.