See Also: Electrolysis(medicine)
Electrolysis(health)
electrolysis(dictionary)
electrolysis(encyclopedia)
electrolysis(dictionary)

electrolysis (sh)




Process in which electric current passed through a substance causes a chemical change, usually the gaining or losing of electrons (see oxidation-reduction).

It is carried out in an electrolytic cell consisting of separated positive and negative electrodes (anode and cathode, respectively) immersed in an electrolyte solution containing ions or in a molten ionic compound. Electric current enters through the cathode; positively charged cations travel to it and combine with electrons. Negatively charged anions give up electrons at the anode. Both thus become neutral molecules. Electrolysis is used extensively in metallurgy to extract or purify metals from ores or compounds and to deposit them from solution (electroplating). Electrolysis of molten sodium chloride yields metallic sodium and chlorine gas; that of a strong solution of sodium chloride in water (brine) yields hydrogen gas, chlorine gas, and sodium hydroxide (in solution); and that of water (with a low concentration of dissolved sodium chloride or other electrolyte) yields hydrogen and oxygen.