What is Electrolysis?

Electrolysis is a method in which a solution containing ions is broken down to its constituent parts using electrical energy. The process of electrolysis is applied to not just separate ions in a liquid but also to refine and purify metals and put metal coatings on objects.

The components required to achieve electrolysis are 

• Electrolyte.
• Electrodes.
• A source of direct electric current. 

Electrolyte:

It is a substance that contains free ions which due to their mobility are electrically conductive. Electrolytes must be present in the liquid, to carry the process of electrolysis, for it is the electrolytes that complete the electrical circuit and enable the separation of the ions.

Electrode:

An electrode by definition is an electrical conductor. In electrolysis, they are in the form of metal or graphite rods that are placed into the liquid. They allow flow of current to and from the electrolyte.

The Process of Electrolysis:

Two electrodes are connected to a source of direct current. Let's assume that in this case it is a battery. One electrode is connected to the positive terminal (Cathode) while the other to the negative terminal of the battery (Anode). The electrodes are immersed in the electrolyte solution.

When current is passed through the ions oxidation and reduction happens. Oxidation is the process where there is a loss of electrons by a substance while Reduction is when a substance gains electrons.

The positive ions loose an electron to the cathode and neutralize there. The cathode gains electrons. By definition reduction takes place in Cathode. The negative ions are attracted to the Anode as they gain an electron from there and neutralize. As Anode looses electrons to the negative ions to neutralize them, Oxidation happens at Anode.

The process is complete, when all the free ions in the electrolyte split to their respective charges to Oxidize or Redox and become neutral elements.

If the solution contains metallic ions, then the metal will be deposited or plated out at the Cathode due to Reduction.

Application of Electrolysis:

A few uses of electrolysis will be electroplating, extraction of metals from ores, electrolytic refining etc.

History of Electrolysis:

William Nicholson, an English Chemist and Sir Anthony Carlisle, an English Surgeon discovered the electrolysis of water. Johan Ritter, discovered the same a little later independently. Ritter discovered the process of electroplating. He built the first electric accumulator. In 1832, Michael Faraday, became the first to describe the Laws of Electrolysis.