Chromium(III) perchlorate

Chromium(III) perchlorate is an inorganic compound, a salt with the chemical formula Cr(ClO₄)₃. It's hexahydrate Cr(ClO₄)₃·6H₂O is a cyan solid that dissolves in water.

Chromium(III) perchlorate

Names
Other names Chromium(III) perchlorate; Chromium triperchlorate
Identifiers
CAS Number	13537-21-8 hexahydrate: 55147-94-9
3D model (JSmol)	Interactive image hexahydrate: Interactive image
ChemSpider	55552 hexahydrate: 21241320
EC Number	236-905-4
PubChem CID	61644 hexahydrate: 12987845
CompTox Dashboard (EPA)	DTXSID40890669 hexahydrate: DTXSID00514430
InChI InChI=1S/3ClHO4.Cr/c3*2-1(3,4)5;/h3*(H,2,3,4,5);/q;;;+3/p-3 Key: ZKJMJQVGBCLHFL-UHFFFAOYSA-K hexahydrate: InChI=1S/3ClHO4.Cr.6H2O/c3*2-1(3,4)5;;;;;;;/h3*(H,2,3,4,5);;6*1H2/q;;;+3;;;;;;/p-3 Key: AWECJTDFTJYSGZ-UHFFFAOYSA-K
SMILES [O-]Cl(=O)(=O)=O.[O-]Cl(=O)(=O)=O.[O-]Cl(=O)(=O)=O.[Cr+3] hexahydrate: O.O.O.O.O.O.[O-]Cl(=O)(=O)=O.[O-]Cl(=O)(=O)=O.[O-]Cl(=O)(=O)=O.[Cr+3]
Properties
Chemical formula	Cr(ClO4)3
Molar mass	350.3489
Appearance	cyan solid
Solubility in water	anhydrous: 58 g/100 mL (25 °C) hexahydrate: 130 g/100 mL (20 °C)[1]
Solubility	soluble in ethanol
Hazards
Occupational safety and health (OHS/OSH):
Main hazards	poisonous
GHS labelling:[2]
Pictograms
Signal word	Danger
Hazard statements	H271, H315, H319, H335
Related compounds
Related compounds	chromium(III) chloride chromium chlorate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Preparation

Chromium perchlorate can prepared by reacting chromium(III) oxide or chromium(III) hydroxide with perchloric acid:

Cr₂O₃ + 6HClO₄ → 2Cr(ClO₄)₃ + 3H₂O

Hydrates

Chromium perchlorate has many hydrates, such as the hexahydrate Cr(ClO₄)₃·6H₂O^[1] and a nonahydrate Cr(ClO₄)₃·9H₂O.^[3] All of them are cyan substances that are soluble in water.

Related compounds

• Cr(ClO₄)₃ will react with NH₃ in suitable conditions to form an orange hexammine complex Cr(ClO₄)₃·6NH₃.^[4] Other compounds with the general formula Cr(ClO₄)₃(NH₃)_x are also known. When x = 3, this compound is red, when x = 4 or 5, it is orange.^[5] The hexammine complex will explode.^[5]

• Cr(ClO₄)₃ can also form complexes with N₂H₄, such as purple Cr(ClO₄)₃·2N₂H₄.^[6]

• Cr(ClO₄)₃ can also form complexes with urea (CO(NH₂)₂), such as Cr(ClO₄)₃·6CO(NH₂)₂ with a hexagonal structure.^[7]