Iron(II) selenate (ferrous selenate) is an inorganic compound with the formula FeSeO₄. It has anhydrous and several hydrate forms. The pentahydrate has the structure, e(H₂O)₄eO₄•H₂O, isomorphous to the corresponding

iron(II) sulfate Iron(II) sulfate (British English: iron(II) sulphate) or ferrous sulfate denotes a range of salts with the formula Fe SO4·''x''H2O. These compounds exist most commonly as the heptahydrate (''x'' = 7) but several values for x are know ...

. Heptahydrate is also known, in form of unstable green crystalline solid.

Preparation

Iron(II) selenate can be prepared by the reaction of saturated sodium selenate and

at 80 °C. When cooled to room temperature, crystalline iron(II) selenate precipitates from the solution. : Na₂SeO₄ (sat.) + FeSO₄ → Na₂SO₄ + FeSeO₄ The reaction of

iron Iron () is a chemical element with Symbol (chemistry), symbol Fe (from la, Wikt:ferrum, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 element, group 8 of the periodic table. It is, Abundanc ...

and

selenic acid Selenic acid is the inorganic compound with the formula . It is an oxoacid of selenium, and its structure is more accurately described as . It is a colorless compound. Although it has few uses, its derivative sodium selenate is used in the prod ...

produces iron(II) selenate as well, but with a side product:A E H Tutton
Selenic Acid and Iron. - Reduction of Selenic Acid by Nascent Hydrogen and Hydrogen Sulphide. - Preparation of Ferrous Selenate and Double Selenates of Iron Group
''Proceedings of the Royal Society A'', 1918 , 94 (241) :352-361 : Fe + H₂SeO₄ → FeSeO₄ + H₂↑ : 3 Fe + 4 H₂SeO₄ → 3 FeSeO₄ + Se + 4 H₂O

Other species containing oxoanion of selenium

Double salt A double salt is a salt that contains two or more different cations or anions. Examples of double salts include alums (with the general formula ) and Tutton's salts (with the general formula ). Other examples include potassium sodium tartrate, a ...

s like the

Tutton's salt Tutton's salts are a family of salts with the formula M2M'(SO4)2(H2O)6 (sulfates) or M2M'(SeO4)2(H2O)6 (selenates). These materials are double salts, which means that they contain two different cations, M+ and M'2+ crystallized in the same regular ...

s (NH₄)₂Fe(SeO₄)₂•6H₂O and K₂Fe(SeO₄)₂•6H₂O are known. In addition to the

ferrous In chemistry, the adjective Ferrous indicates a compound that contains iron(II), meaning iron in its +2 oxidation state, possibly as the divalent cation Fe2+. It is opposed to " ferric" or iron(III), meaning iron in its +3 oxidation state, suc ...

(Fe²⁺) salt, the

ferric In chemistry, iron(III) refers to the element iron in its +3 oxidation state. In ionic compounds (salts), such an atom may occur as a separate cation (positive ion) denoted by Fe3+. The adjective ferric or the prefix ferri- is often used to sp ...

(Fe³⁺) salt iron(III) selenate, Fe₂(SeO₄)₃, has also been reported. However, iron(II) selenite (FeSeO₃) is unknown, though the selenite and pyroselenite of iron(III) was published.Pinaev, G. F.; Stukan, R. A.; Makarov, E. F.. Moessbauer effect in iron(3+) selenites. ''Zhurnal Neorganicheskoi Khimii'', 1977. 22 (7): 1731-1733

References

{{Selenates Iron(II) compounds Selenates