Editing Ferrous (section)

==Ferrous salts and complexes==
Typically iron(II) salts, like the "[[iron(II) chloride|chloride]]" are [[aquo complex]]es with the formulas {{chem2|[Fe(H2O)6](2+)}}, as found in [[Ammonium iron(II) sulfate|Mohr's salt]].<ref name="earn">{{cite book |author=Earnshaw, A. |author2=Greenwood, N. N. |title=Chemistry of the elements |publisher=Butterworth-Heinemann |location=Oxford |year=1997 |isbn=0-7506-3365-4 |edition=2nd}}</ref> 

The aquo ligands on iron(II) complexes are labile. It reacts with [[1,10-Phenanthroline|1,10-phenanthroline]] to give the blue iron(II) derivative:

When metallic iron (oxidation state 0) is placed in a solution of [[hydrochloric acid]], iron(II) chloride is formed, with release of [[hydrogen]] gas, by the reaction
: {{chem2|Fe^{0} + 2 H(+) -> Fe(2+) + H2}}

Iron(II) is oxidized by hydrogen peroxide to [[iron(III)]], forming a [[hydroxyl radical]] and a [[hydroxide ion]] in the process. This is the [[Fenton reaction]]. Iron(III) is then reduced back to iron(II) by another molecule of hydrogen peroxide, forming a [[hydroperoxyl]] radical and a [[hydrogen atom|proton]]. The net effect is a [[disproportionation]] of hydrogen peroxide to create two different oxygen-radical species, with water (H<sup>+</sup>&nbsp;+&nbsp;OH<sup>−</sup>) as a byproduct.<ref>{{cite journal |doi=10.1021/acs.chemrev.0c00977 |title=Biomedicine Meets Fenton Chemistry |date=2021 |last1=Tang |first1=Zhongmin |last2=Zhao |first2=Peiran |last3=Wang |first3=Han |last4=Liu |first4=Yanyan |last5=Bu |first5=Wenbo |journal=Chemical Reviews |volume=121 |issue=4 |pages=1981–2019 |pmid=33492935 |s2cid=231712587 }}</ref> 

{{NumBlk|:| Fe<sup>2+</sup> + H<sub>2</sub>O<sub>2</sub> → Fe<sup>3+</sup> + HO<sup>•</sup> + OH<sup>−</sup>|{{EquationRef|1}}}}
{{NumBlk|:| Fe<sup>3+</sup> + H<sub>2</sub>O<sub>2</sub> → Fe<sup>2+</sup> + HOO<sup>•</sup> + H<sup>+</sup>|{{EquationRef|2}}}}

The [[free radical]]s generated by this process engage in secondary reactions, which can degrade many organic and biochemical compounds.[[File:Fe(bipy)3 redox.svg|thumb|360px|center|Redox reaction of [Fe(bipyridine)<sub>3</sub>]<sup>2+</sup>.]]