Aluminum metal is made by electrolysis of alumina dissolved in the molten mineral, cryolite. Copper and other minerals are purified by electrolysis. A bar of impure copper is made the anode and a bar of pure copper is made the cathode. During electrolysis, the impure copper anode is dissolved into copper ions. The pure copper it contains plates out on the cathode.
All impurities fall to the bottom of the electrolytic cell and are removed later.
Important chemicals produced commercially by electrolysis include manganese dioxide, hydrogen peroxide, chlorates, and perchlorates. Hydrogen peroxide and perchlorates are used in rocket fuels. Electrolysis is also used to anodize metals to make their surfaces more decorative and resistant to corrosion. Laws of electrolysis. The English chemist Michael Faraday was one of the first scientists to investigate electrolysis.