Package: 11lbs = 5000g
Chrome alum or Chromium(III) potassium sulfate is the potassium double sulfate of chromium. Its chemical formula is KCr(SO4)2 and it is commonly found in its dodecahydrate form as KCr(SO4)2·12(H2O). It is used in leather tanning and experiments.
It was also used in gelatine emulsions in photographic film as hardener.