The term ‘ electrolysis ‘ comes from the Greek and means ‘to break with electricity’. It is a process that consists in carrying out chemical transformations thanks to the supply of electrical energy ; consequently, there is the conversion of electrical energy into chemical energy. This process does not occur spontaneously as it is necessary to supply electrical energy from outside to the system for it to occur. In 1832, it was the physicist Michael Faraday who studied electrolysis and enunciated the two main laws of the process:
- the amount of elements produced by an electrolysis process is directly proportional to the amount of charge that has passed through the electrolytic cell;
- given the same charge, the quantity of the different elements obtained is proportional to the equivalent weights of the chemical species.
Electrolysis: What is it?
The term ‘ electrolysis ‘ comes from the Greek and means ‘to break with electricity’. It is a process that consists in carrying out chemical transformations thanks to the supply of electrical energy ; consequently, there is the conversion of electrical energy into chemical energy. This process does not occur spontaneously as it is necessary to supply electrical energy from outside to the system for it to occur. In 1832, it was the physicist Michael Faraday who studied electrolysis and enunciated the two main laws of the process:
- the amount of elements produced by an electrolysis process is directly proportional to the amount of charge that has passed through the electrolytic cell;
- given the same charge, the quantity of the different elements obtained is proportional to the equivalent weights of the chemical species.
Electrolysis: How the Chemical Process Works
Electrolysis experiments carried out in the laboratory are usually conducted on aqueous solutions . In this case, two electrodes are immersed in the aqueous solution and a direct electric current is applied to them: according to the law of attraction between opposite charges , positive ions (cations) are attracted to the negative electrode (cathode) and negative ions (anions) to the positive electrode (anode). Consequently, when a positive ion comes into contact with the negative electrode, it is forced to acquire electrons from it, i.e. it undergoes a reduction . On the other hand, when a negative ion comes into contact with the positive electrode, it gives up its electrons to it, i.e. it undergoes an oxidation .
Electrolysis: the applications
One of the most common substances in the industrial field and produced through electrolysis is chlorine : in this case the process is applied to sodium chloride solutions. Another very widespread application of electrolysis is electrogravimetry , a method that allows to determine quantitatively and very accurately the metal content of a sample brought in aqueous solution. Among the most recent applications of the process, it is necessary to remember the treatments of pollutants contained in industrial wastewater, especially those concerning chlorinated organic compounds, some of which are carcinogenic.
