Chromium(III) chloride
Chromium trichloride
- Red-violet shining leaflets (anhydrous)
- Green ( hexahydrate)
Fixed
2.87 g · cm -3
1152 ° C
- (anhydrous), sparingly soluble in water and ethanol
- 590 g / l of water (hexahydrate )
Risk
1870 mg · kg -1 ( LD50, rat, oral)
Template: Infobox chemical / molecular formula search available
Chromium ( III) chloride, the chromium salt of an acid with the formula CrCl3. It crystallizes as a hydrate of chromium (III) chloride hexahydrate ( CrCl 3 · 6H 2 O ).
Production and representation
Chromium ( III) chloride can be obtained by the reaction of chromium chloride.
Properties
The hexahydrate [ CrCl2 (H2O ) 4] Cl · 2H2O
It forms crystalline layer structures, the red-violet shine between which van der Waals forces. The salt in pure form is sparingly soluble in water and insoluble in ethanol. Only in the presence of traces of chromium (II ) chloride ( CrCl2 ) (or other reducing agent ) is catalytically possible in water under high heat output a solution process. In solution, differently colored hydratisomere aqua complexes can form, for example, the dark green Dichlorotetraaquachrom (III ) chloride, the bright green Chloropentaaquachrom (III ) chloride or the violet Hexaaquachrom (III ) chloride. This stand between these complexes following equilibria:
Production
Chromium ( III) chloride can be synthesized from metal chromium in a stream of chlorine at 600 ° C. Likewise, the production of chromium ( III) oxide and carbon in a stream of chlorine in excess of 1200 ° C is possible.
Use
As the catalyst for the manufacture of other chromium compounds, chromium plating in electroplating and Waterproof impregnation.