What does electrolytic reduction means?

Question

As in... " The most important metal Al is made by the electrolytic reduction alumia".

Answer 1

The electrolytic reduction of alumina means that Al3+ ions in molten aluminium oxide (alumina) are forced to accept three electrons each (which is reduction) to form aluminium metal.

Look up the Hall Cell to find out more.

Answer 2

The components which make contact with the electrolyte are called ELECTRODES. The electrode which is attached to the negative pole of the battery, and which supplies electrons to the electrolyte, is called the CATHODE. Reduction takes place at the cathode.

The electrode which is attached to the positive pole of the battery, and which accepts electrons from the electrolyte, is called the ANODE. Oxidation takes place at the anode.

When a direct electric current is passed through an ELECTROLYTE (such as a molten salt or an aqueous solution of a salt, acid or base), chemical reactions take place at the contacts between the circuit and the solution. This process is called ELECTROLYSIS
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Aluminium is obtained by the electrolytic reduction of its molten oxide, alumina (Al2O3). Because alumina has a very high melting point (2045 ºC), the mineral cryolite (Na3AlF6) is added to lower the melting point in order that the elctrolysis may be carried out at about 950 ºC. The electrolytic cell has carbon anodes and a carbon cathode (which forms the lining of the tank in which the electrolysis takes place). Carbon dioxide is formed at the anodes, and aluminium at the cathode. It is heavier than the molten alumina/cryolite mixture, and sinks to the bottom of the cell, where it is tapped off. The procedure is known as the Hall-Heroult process.