What is Electrolysis of water?
{{no sources|date=September 2021}} [[File:Schemas electrolyse h2o.svg|thumb|A diagram of the '''electrolysis of water'''.]] '''Electrolysis of water''' is the [[decomposition]] of [[water]] into [[oxygen]] and [[hydrogen]] gas. This technique can be used to produce [[breath|breathable]] oxygen or hydrogen gas as a fuel source, referred to as [[hydrogen fuel]]. However, that method is more expensive than the [[industry|industrial]] way to produce hydrogen fuel from [[natural gas]].{{fact|date=April 2018}} This is what is referred to as a non-spontaneous reaction which requires impetus. At the [[cathode]], [[reduction]] (in this case, the gain of electrons) occurs. At the [[anode]], [[oxidation]] (in this case, the loss of electrons) occurs. Normally, the reaction is balanced with either an [[acid]] or a [[Base (chemistry)|base]] as shown in the [[equation]]s below. :the reduction at cathode: 2 H<sup>+</sup><sub>(''[[Aqueous solution|aq]]'')</sub> + 2e<sup>−</sup> → H<sub>2</sub><sub>(''[[gaseous|g]]'')</sub> :the oxidation at anode: 2 H<sub>2</sub>O<sub>(''[[liquid|l]]'')</sub> → O<sub>2(''g'')</sub> + 4 H<sup>+</sup><sub>(''aq'')</sub> + 4e<sup>−</sup> That two reactions are half reactions. They are balanced with an acid. Commonly [[hydrochloric acid]] or [[sulfuric acid]] is used. However, the half reactions can also be balanced with a base, for example with [[sodium hydroxide]]. :the reduction at cathode: 2 H<sub>2</sub>O<sub>(''l'')</sub> + 2e<sup>−</sup> → H<sub>2(''g'')</sub> + 2 OH<sup>−</sup><sub>(''aq'')</sub> :the oxidation at anode: 4 OH<sup>−</sup><sub>(''aq'')</sub> → O<sub>2(''g'')</sub> + 2 H<sub>2</sub>O<sub>(''l'')</sub> + 4 e<sup>−</sup> Combining one pair of half reactions leads to an overall reaction, which is then the decomposition of water into oxygen and hydrogen. :complete reaction: 2 H<sub>2</sub>O<sub>(''l'')</sub> → 2 H<sub>2(''g'')</sub> + O<sub>2(''g'')</sub> {{science-stub}} [[Category:Chemistry]]