Electrolytic cell electrons from the cathode and deposits on the cathode as sodium metal. NaCl dissolved in water can also be electrolyzed. The anode oxidizes chloride ions (Cl), and Cl gas is produced. However, at the cathode, instead of sodium ions being reduced to sodium metal, water molecules are reduced to hydroxide ions (OH) and hydrogen gas (H). The overall result of the electrolysis is the production of chlorine gas and aqueous sodium hydroxide (NaOH) solution. Commercially, electrolytic cells are used in electrorefining and electrowinning of several non-ferrous metals. Almost all high-purity aluminium, copper, zinc and lead is produced industrially in electrolytic
Electrode potential that only the magnitude expressed according to the convention (2) be called "the electrode potential". To avoid possible ambiguities, the electrode potential thus defined can also be referred to as "Gibbs–Stockholm electrode potential". In both conventions, the standard hydrogen electrode is defined to have a potential of 0 V. Both conventions also agree on the sign of "E" for a half-cell reaction when it is written as a reduction. The main difference between the two conventions is that upon reversing the direction of a half-cell reaction "as written", according to convention (1) the sign of "E" also switches, whereas in