Chromium(III) sulfate

Chromium(III) sulfate

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Names
IUPAC name Chromium(III) sulfate
Other names Basic chromium sulfate, chromic sulfate
Identifiers
CAS Number	10101-53-8 Y 13520-66-6 (dodecahydrate) N
ChemSpider	21241287 N
Jmol 3D model	Interactive image
PubChem	24930
UNII	Y0C99N5TMZ Y
InChI InChI=1S/2Cr.3H2O4S.12H2O/c;;3*1-5(2,3)4;;;;;;;;;;;;/h;;3*(H2,1,2,3,4);12*1H2/q2*+3;;;;;;;;;;;;;;;/p-6 N Key: ANNXSSGQVXBUEI-UHFFFAOYSA-H N InChI=1/2Cr.3H2O4S.12H2O/c;;3*1-5(2,3)4;;;;;;;;;;;;/h;;3*(H2,1,2,3,4);12*1H2/q2*+3;;;;;;;;;;;;;;;/p-6 Key: ANNXSSGQVXBUEI-CYFPFDDLAL
SMILES [Cr+3].[Cr+3].[O-]S(=O)(=O)[O-].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O.O.O.O.O.O.O.O.O.O.O.O.O
Properties
Chemical formula	Cr2(SO4)3 • 12H2O
Molar mass	392.16 g/mol 608.363 g/mol (dodecahydrate) 716.45 g/mol (octadecahydrate)
Appearance	reddish-brown crystals (anhydrous), purple crystals (hydrated)
Density	3.10 g/cm3 (anhydrous) 1.86 g/cm3 (pentadecahydrate) 1.709 g/cm3 (octadecahydrate)
Melting point	90 °C
Boiling point	decomposes to chromic acid
Solubility in water	insoluble (anhydrous) soluble (hydrated)
Solubility	soluble in alcohol practically insoluble in acid
Vapor pressure	{{{value}}}
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N verify (what is YN ?)
Infobox references

Chromium(III) sulfate usually refers to the inorganic compound with the formula Cr₂(SO₄)₃ • 12(H₂O). This consists of the hydrated sulfate salt of the metal aquo complex with the formula [Cr(H₂O)₆]³⁺, which is responsible for the purple color of this salt. It is widely used in the tanning of leather, with associated environmental damage.

Properties

Heating chromium(III) sulfate leads to partial dehydration to give a hydrated green salt (CAS#15244-38-9) and eventually the anhydrous derivative (CAS#10101-53-8).

Production

Basic chromium sulfate is produced from chromate salts by reduction with sulfur dioxide, although other methods exist. The hydrous form may be formed by the reaction of chromium(III) oxide and sulfuric acid.

Cr₂O₃ + 3 H₂SO₄ → Cr₂(SO₄)₃ + 3 H₂O

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