CAS Number: 7788-99-0
Linear Formula: CrK(SO4)2•12H2O
Molecular Weight: 499.40
IUPAC Name: Chromium potassium sulfate dodecahydrate
Other Names: Potassium chromium(III) sulfate, Alum chrome
Chromium(III) potassium sulfate or Chrome alum is the potassium double sulfate of chromium. Its chemical formula is CrK(SO4)2 and it is commonly found in its dodecahydrate form as CrK(SO4)2·12H2O.
Chromium alum is used in the tanning of leather as chromium(III) stabilizes the leather by cross linking the collagen fibers within the leather. However, this application is obsolete because the simpler chromium(III) sulfate is preferred.It was also used in gelatine emulsions in photographic film.
