Chromium(II) sulfate refers to
inorganic compounds with the
chemical formula
In chemistry, a chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbol ...
CrSO
4·n H
2O. Several closely related
hydrated salts are known. The pentahydrate is a blue solid that dissolves readily in water. Solutions of chromium(II) are easily oxidized by air to Cr(III) species. Solutions of Cr(II) are used as specialized reducing agents of value in
organic synthesis.
[A. Zurqiyah and C. E. Castro "Reduction of Conjugated Alkenes With Chromium(II) Sulfate: Diethyl Succinate" Organic Syntheses, Vol. 49, p.98 (1969).]
The salt is produced by treating chromium metal with aqueous sulfuric acid:
:Cr + H
2SO
4 + 5 H
2O → CrSO
4·5 H
2O + H
2
It can be produced through the reaction of
sulfate
The sulfate or sulphate ion is a polyatomic anion with the empirical formula . Salts, acid derivatives, and peroxides of sulfate are widely used in industry. Sulfates occur widely in everyday life. Sulfates are salts of sulfuric acid and many ...
salts and
chromium(II) acetate
Chromium(II) acetate hydrate, also known as chromous acetate, is the coordination compound with the formula Cr2(CH3CO2)4(H2O)2. This formula is commonly abbreviated Cr2(OAc)4(H2O)2. This red-coloured compound features a quadruple bond. The prepara ...
or, for in situ use, the reduction of
chromium(III) sulfate
Chromium(III) sulfate usually refers to the inorganic compounds with the formula Cr2(SO4)3.x(H2O), where x can range from 0 to 18. Additionally, ill-defined but commercially important "basic chromium sulfates" are known. These salts are usually ei ...
with zinc.
[
]
Structure
In aqueous solutions chromium(II) sulfate forms metal aquo complex
In chemistry, metal aquo complexes are coordination compounds containing metal ions with only water as a ligand. These complexes are the predominant species in aqueous solutions of many metal salts, such as metal nitrates, sulfates, and perchlorat ...
es, presumably with six water ligands. The structures of the crystalline salts are similar to the corresponding hydrates of copper(II) sulfate
Copper(II) sulfate, also known as copper sulphate, is an inorganic compound with the chemical formula . It forms hydrates , where ''n'' can range from 1 to 7. The pentahydrate (''n'' = 5), a bright blue crystal, is the most commonly encountered h ...
: pentahydrate, trihydrate, monohydrate, and anhydrous derivatives of chromous sulfate are known. In all of these compounds, the Cr(II) centre adopts octahedral coordination geometry
In chemistry, octahedral molecular geometry, also called square bipyramidal, describes the shape of compounds with six atoms or groups of atoms or ligands symmetrically arranged around a central atom, defining the vertices of an octahedron. The oc ...
, being coordinated to six oxygen centers provided by a combination of water and sulfate ligands.
References
Chromium(II) compounds
Sulfates
Chromium–oxygen compounds
{{Inorganic-compound-stub