KAI(SO4)2 is the chemical make-up of the compound potassium alum, also known as potassium aluminum sulfate. The chemical is most commonly found in its dodecahydrate form: KAI(SO4)2 12(H2O).
Potassium alum is made up of 8.2418 percent potassium, 5.6876 percent aluminum, 5.0993 percent hydrogen, 13.5185 percent sulfur and 67.4527 percent oxygen. It is a naturally occurring sulfate mineral that is often formed as encrustations on rocks.
Potassium alum is commonly used in water purification, leather tanning, fireproof textiles and baking powder. It also has cosmetic uses as an aftershave, as a deodorant and to reduce bleeding in minor cuts. In China, it is used in a medicine called ming fan.