Editing Electrolysis (section)

===Oxidation and reduction at the electrodes===
[[Oxidation]] of ions or neutral molecules occurs at the [[anode]]. For example, it is possible to oxidize ferrous ions to ferric ions at the anode:
: Fe{{su|p = 2+}}(aq) → Fe{{su|p = 3+}}(aq) + e<sup>−</sup> 
[[Redox|Reduction]] of ions or neutral molecules occurs at the [[cathode]]. It is possible to reduce [[ferricyanide]] ions to [[ferrocyanide]] ions at the cathode:
:Fe(CN){{su|p=3-|b=6}} + e<sup>−</sup> → Fe(CN){{su|p=4-|b=6}}

Neutral molecules can also react at either of the electrodes. For example: ''p''-benzoquinone can be reduced to hydroquinone at the cathode:

: [[Image:P-Benzochinon.svg|35px]] + 2 e<sup>−</sup> + 2 H<sup>+</sup> → [[Image:Hydrochinon2.svg|90px]]

In the last example, H<sup>+</sup> ions (hydrogen ions) also take part in the reaction and are provided by the acid in the solution, or by the solvent itself (water, methanol, etc.). Electrolysis reactions involving H<sup>+</sup> ions are fairly common in acidic solutions. In aqueous alkaline solutions, reactions involving OH<sup>−</sup> (hydroxide ions) are common.

Sometimes the solvents themselves (usually water) are oxidized or reduced at the electrodes. It is even possible to have electrolysis involving gases, e.g. by using a [[gas diffusion electrode]].