Ferrous - Wikipedia
2019-6-25 · In chemistry, the adjective ferrous indicates a compound that contains iron in the +2 oxidation state, possibly as the divalent cation Fe2+. It is opposed to "ferric", which indicates presence of iron in a +3 oxidation state, such as the trivalent cation Fe3+.[1] This usage has been largely replaced by the IUPAC nomenclature, which calls for ...