Ammonium Chromic Sulfate

Title: Ammonium Chromic Sulfate
CAS Registry Number: 13548-43-1
Additional Names: Ammonium disulfatochromate(III); chromic ammonium sulfate
Molecular Formula: CrH4NO8S2
Molecular Weight: 262.16
Percent Composition: Cr 19.83%, H 1.54%, N 5.34%, O 48.82%, S 24.46%
Line Formula: NH4Cr(SO4)2
Literature References: Prepd by crystallization from a soln contg equimolar amounts of Cr2(SO4)3 and (NH4)2SO4: Howarth in ACS Monograph Series no. 132, entitled "Chromium," vol. 1, M. J. Udy, Ed. (Reinhold, New York, 1956) p 287; electrolytic prepn: Nishihara et al., JP 60 2164 (1960), C.A. 55, 5200e (1961).
Derivative Type: Dodecahydrate
Additional Names: Chrome alum ammonium
Properties: Small dark-violet or violet-blue, octahedral, cubic crystals; ruby-red by transmitted light. mp 94°; loses 9H2O on melting and the remaining H2O by 300°. d25 1.72. Readily sol in water; slightly sol in alcohol. Aq soln is violet when cold, green when hot.
Melting point: mp 94°; loses 9H2O on melting and the remaining H2O by 300°
Density: d25 1.72
Use: Mordant in textile industry; in manuf of electrolytic Cr metal.
Ammonium Citrate, Dibasic Ammonium Cobaltous Phosphate Ammonium Cobaltous Sulfate Ammonium Cupric Chloride Ammonium Dichromate(VI)