Electrolysis

Electrolysis is a scientific way of 'splitting' substances. It means 'electric-splitting' and involves the separation of substances through an electric current.

Metals above carbon in the reactivity series (potassium, sodium, lithium, calcium, magnesium and aluminium) are extracted by electrolysis.

Uses

Electrolysis is used in the mining industry to split reactive metals from their ores after they are taken from the ground.

Electroplating is also used to plate (cover) things with metal because it costs less than using, for example, solid gold to make jewellery.

Electrolysis can be used by a trained doctor or esthetician to remove hair. This is called electrology. The "galvanic" method of electrology uses electrolysis to produce a very small amount of a caustic solution, containing sodium hydroxide and water, by running an electrical current through a metal probe inside of the hair follicle. The method uses the body's tissues, which contain water and salts (electrolytes) as an electrolytic cell. The caustic solution reacts with the cells inside of the follicle, and damages them so that they cannot grow a hair anymore.

In modern practice, the probe is also heated up using electricity (called diathermy), which makes the chemical solution work more effectively, known as the "blend" electrology method. This heat can also be used by itself, and is used by electrologists, but does not involve electrolysis. Instead, this is a form of thermolysis, damaging hair cells using heat energy.

Electrolysis makes the anions (negative ions) go to the anode (positive electrode) and the cations (positive ions) go to the cathode (negative electrode). So, for example, oxygen would go to the anode and iron would go to the cathode.

Related pages

• Electrolysis of water