Chromium(II) sulfate

Chromium(II) sulfate

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Names
IUPAC name Chromium(2+) sulfate
Other names chromous sulfate, chromous sulphate
Identifiers
CAS Number	(pentahydrate), 19512-13-1 (trihydrate), 13825-86-0 (anhydrous) 15928-77-5 (pentahydrate), 19512-13-1 (trihydrate), 13825-86-0 (anhydrous)
ChemSpider	55589
PubChem	61686
InChI Key: RYPRIXSYXLDSOA-UHFFFAOYSA-L Key: RYPRIXSYXLDSOA-NUQVWONBAQ
Properties
Chemical formula	CrSO4·5 H2O
Molar mass	238.13 (pentahydrate)
Appearance	blue solid (pentahydrate)
Solubility in water	21 g/100 mL (0°C, pentahydrate)
Vapor pressure	{{{value}}}
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 refers to inorganic compounds with the chemical formula CrSO₄·n H₂O. 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.

The salt is produced by treating chromium metal with aqueous sulfuric acid:

Cr + H₂SO₄ + 5 H₂O → CrSO₄·5 H₂O + H₂

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

Structure

In aqueous solutions chromium(II) sulfate forms metal aquo complexes, presumably with six water ligands. The structures of the crystalline salts are similar to the corresponding hydrates of copper(II) sulfate: pentahydrate, trihydrate, monohydrate, and anhydrous derivatives of chromous sulfate are known. In all of these compounds, the Cr(II) centre adopts octahedral coordination geometry, being coordinated to six oxygen centers provided by a combination of water and sulfate ligands.

References

Salts and the ester of the sulfate ion
H2SO4																	He
Li2SO4	BeSO4											B	(RO)2SO3	(NH4)2SO4 N2H6SO4 (NH3OH)2SO4	O	F	Ne
Na2SO4 NaHSO4	MgSO4											Al2(SO4)3	Si	P	SO42−	Cl	Ar
K2SO4 KHSO4	CaSO4	Sc2(SO4)3	Ti(SO4)2 TiOSO4	V2(SO4)3 VOSO4	CrSO4 Cr2(SO4)3	MnSO4	FeSO4 Fe2(SO4)3	CoSO4, Co2(SO4)3	NiSO4	CuSO4	ZnSO4	Ga2(SO4)3	Ge	As	Se	Br	Kr
Rb2SO4	SrSO4	Y2(SO4)3	Zr(SO4)2	Nb	Mo	Tc	Ru	Rh	PdSO4	Ag2SO4	CdSO4	In2(SO4)3	SnSO4	Sb2(SO4)3	Te	I	Xe
Cs2SO4	BaSO4		Hf	Ta	W	Re	Os	Ir	Pt	Au	Hg2SO4, HgSO4	Tl2SO4	PbSO4	Bi2(SO4)3	Po	At	Rn
Fr	Ra		Rf	Db	Sg	Bh	Hs	Mt	Ds	Rg	Cn	Uut	Fl	Uup	Lv	Uus	Uuo
		↓
		La	Ce2(SO4)3 Ce(SO4)2	Pr2(SO4)3	Nd	Pm	Sm	Eu	Gd	Tb	Dy	Ho	Er	Tm	Yb2(SO4)3	Lu
		Ac	Th	Pa	U(SO4)2 UO2SO4	Np	Pu	Am	Cm	Bk	Cf	Es	Fm	Md	No	Lr