Chrome alum
Chrome alum, also known as chromium potassium sulfate, is a chemical compound. Its chemical formula is KCr(SO4)2. It contains chromium, potassium, and sulfate ions. The chromium is in its +3 oxidation state.
Properties[change | change source]
It is a dark purple solid. It is normally attached to extra water molecules. It dissolves in water.
Preparation[change | change source]
It is made by reducing potassium dichromate with sulfur dioxide.
Uses[change | change source]
It was used in making leather; now chromium(III) sulfate is used instead.