Electrolytic cell

Cuba electrolytic, showing the electrodes and the power supply generated by the electric current.

The electrolytic cell or electrolytic cell is the device used for the decomposition by means of an electric current of ionized substances called electrolytes.

Electrolytes can be acids, bases, or salts.

The process of dissociation or decomposition carried out in the electrolytic cell is called electrolysis.

In electrolysis we can distinguish three phases:

• Ionization - It is a previous phase before the application of the current and to effect the substance to decompose must be ionized, which is achieved by dissolving it or melting it.
• Orientation - In this phase, once the current has been applied, the ions are directed, according to their electrical load, towards the corresponding poles (+) or (-)
• Download - Negative ions or anions yield electrons to anode (+) and positive ions or cationes take electrons from the cathode (-).

In order for the ions to be highly mobile, electrolysis is usually carried out in solution or in salts. Except in cases such as the direct synthesis of sodium hypochlorite, the electrodes are separated by a diaphragm to avoid the reaction of the products formed.

For the synthesis of soda, a mercury cathode has also been used. This dissolves the sodium metal in the form of an amalgam and is thus separated.