Title: Chromic Potassium Sulfate
CAS Registry Number: 10141-00-1
Additional Names: Potassium chromic sulfate; potassium disulfatochromate(III)
Molecular Formula: CrKO8S2
Molecular Weight: 283.22
Percent Composition: Cr 18.36%, K 13.80%, O 45.19%, S 22.64%
Line Formula: KCr(SO4)2
Literature References: Dodecahydrate produced by reduction of K2Cr2O7 with SO2: Copson in ACS Monograph Series no. 132, entitled "Chromium," vol. 1, M. J. Udy, Ed. (Reinhold, New York, 1956) p 281; electrolytic manuf: Nishihara et al., JP 60 2164 C.A. 55, 5200e (1961).
Derivative Type: Dodecahydrate
Additional Names: Chrome alum
Literature References: K[Cr(SO6H4)2(H2O)2].6H2O: Duval, Chim. Anal. (Paris) 44, 102 (1962), C.A. 57, 9479d (1962).
Properties: Large, violet-red to black, octahedral, cubic crystals; ruby-red under transmitted light. d25 1.83. mp 89°; at 400° loses all its H2O. Sol in 4 parts cold, 2 parts boiling water; practically insol in alcohol. The aq soln is violet when cold, green when hot. The violet color returns after a few weeks at room temp.
Melting point: mp 89°
Density: d25 1.83
Use: Mordant for dyeing fabrics uniformly; tanning leather; printing calico; rendering glue and gum insol; manuf ink, other chromium salts; waterproofing fabrics; hardening photographic emulsions. |