It is understood by electrolysis the chemical reactions that occur in electrodes, they are used for the reduction of metals, our study concerns Alkaline and Alkaline-earth metals. In this case it is the Igneous Electrolysis, this process allows to obtain pure elements from compound substances.
igneous electrolysis: Occurs at high temperatures and in the absence of water. In this type of electrolysis, the ionic solid must be liquefied by heating (fusion) for the ions to move more easily to the electrodes and then discharge.
The ions in this case come from the metals: Magnesium (alkaline earth metal) or Sodium (alkali metal). See the process equations:
mg2+ + 2é → Mg0
At+ + is → Na0
These are the cathodic semi-reactions of Igneous Electrolysis. The index 0 on the products indicates that the element is in its natural form.
Aqueous electrolysis: In this case, there are the ions resulting from the ionic dissociation of the electrolyte and the ions from the aqueous medium that also participate in the process (H+ cations and OH- anions from the self-ionization of water).
As is known, the H+ ions present in aqueous electrolysis are easier to discharge compared to Na+ in G2+, and therefore this method is not applied to the Electrolysis of Alkaline and Alkaline-Earth Metals. Now let's see where the raw material for the production of these metals is taken from:
Seawater provides the substances: Sodium Chloride (NaCl) and Magnesium Chloride (MgCl2), and through igneous electrolysis it is possible to obtain Sodium and Magnesium in the pure state.
By Líria Alves
Graduated in Chemistry
Brazil School Team
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Electrolysis - Physicochemical - Chemistry - Brazil School
Source: Brazil School - https://brasilescola.uol.com.br/quimica/eletrolise-metais-alcalinos-alcalinoterrosos.htm