Chromium(II) sulfate

Chromium(II) sulfate
	; Crystalline sample wet with ethanol
	; Structure of chromium(II) sulfate pentahydrate (CrSO4·5H2O) Chromium, Cr Sulfur, S Oxygen, O Hydrogen, H
Names
	IUPAC name Chromium(2+) sulfate
	Other names chromous sulfate, chromous sulphate
Identifiers
CAS Number	13825-86-0 (anhydrous); 15928-77-5 (pentahydrate); 19512-13-1 (trihydrate);
3D model (JSmol)	anhydrous: Interactive image; pentahydrate: Interactive image;
ChemSpider	55589 (anhydrous);
PubChem CID	61686 (anhydrous);
UNII	Y0C99N5TMZ (anhydrous) ; 990MUV05EC (pentahydrate) ;
CompTox Dashboard (EPA)	DTXSID80160555 ;
	InChI Key: RYPRIXSYXLDSOA-UHFFFAOYSA-L; Key: RYPRIXSYXLDSOA-NUQVWONBAQ;
	SMILES anhydrous: [Cr+2].[O-]S(=O)(=O)[O-]; pentahydrate: [OH2+][Cr-3]([OH2+])([OH2+])([OH2+])O(S(=O)(=O)[O-]).O;
Properties
Chemical formula	CrSO4 (anhydrous); CrSO4·5H2O (pentahydrate)
Molar mass	148.05 g/mol (anhydrous); 238.13 g/mol (pentahydrate)
Appearance	Blue crystalline solid (pentahydrate)
Solubility in water	21 g/(100 mL) (0°C, pentahydrate)
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Chromium(II) sulfate is an inorganic compound with the chemical formula Cr S O₄. It often comes as hydrates CrSO₄·nH₂O. Several hydrated salts are known. The pentahydrate CrSO₄·5H₂O 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.^[1]

The salt is produced by treating chromium metal with aqueous sulfuric acid:^[2]

Cr + H₂SO₄ + 5 H₂O → CrSO₄·5H₂O + H₂

It can be produced through the reaction of sulfate salts and chromium(II) acetate^[3] or, for in situ use, the reduction of chromium(III) sulfate with zinc.^[1]

^ ^a ^b A. Zurqiyah and C. E. Castro "Reduction of Conjugated Alkenes With Chromium(II) Sulfate: Diethyl Succinate" Organic Syntheses, Vol. 49, p.98 (1969).doi:10.15227/orgsyn.049.0098
^ Handbook of Preparative Inorganic Chemistry, 2nd Ed. Edited by G. Brauer, Academic Press, 1963, NY. Vol. 2. p. 1365.
^ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8.

[OS-1] A. Zurqiyah and C. E. Castro "Reduction of Conjugated Alkenes With Chromium(II) Sulfate: Diethyl Succinate" Organic Syntheses, Vol. 49, p.98 (1969).doi:10.15227/orgsyn.049.0098

[2] Handbook of Preparative Inorganic Chemistry, 2nd Ed. Edited by G. Brauer, Academic Press, 1963, NY. Vol. 2. p. 1365.

[3] Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8.

[1]

[2]

[3]

Names
Crystalline sample wet with ethanol
Structure of chromium(II) sulfate pentahydrate (CrSO₄·5H₂O) Chromium, Cr Sulfur, S Oxygen, O Hydrogen, H
IUPAC name Chromium(2+) sulfate
Other names chromous sulfate, chromous sulphate
Identifiers
CAS Number	13825-86-0 (anhydrous) 15928-77-5 (pentahydrate) 19512-13-1 (trihydrate)
3D model (JSmol)	anhydrous: Interactive image pentahydrate: Interactive image
ChemSpider	55589 (anhydrous)
PubChem CID	61686 (anhydrous)
UNII	Y0C99N5TMZ (anhydrous)^Y 990MUV05EC (pentahydrate)^Y
CompTox Dashboard (EPA)	DTXSID80160555
InChI Key: RYPRIXSYXLDSOA-UHFFFAOYSA-L Key: RYPRIXSYXLDSOA-NUQVWONBAQ
SMILES anhydrous: [Cr+2].[O-]S(=O)(=O)[O-] pentahydrate: [OH2+][Cr-3]([OH2+])([OH2+])([OH2+])O(S(=O)(=O)[O-]).O
Properties
Chemical formula	CrSO₄ (anhydrous) CrSO₄·5H₂O (pentahydrate)
Molar mass	148.05 g/mol (anhydrous) 238.13 g/mol (pentahydrate)
Appearance	Blue crystalline solid (pentahydrate)
Solubility in water	21 g/(100 mL) (0°C, pentahydrate)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references