Potassium aluminium sulfate
potassium alum crystal with unequal distribution of the face area
Potassium aluminium sulfate, or potash alum, or potassium alum, is a chemical compound. Its chemical formula is KAl(SO4)2. It contains potassium, aluminium, and sulfate ions.
It is a white acidic solid. It reacts with sodium bicarbonate to make carbon dioxide gas. It does exist naturally. It can often be found as a mineral.
It is made by reacting aluminium sulfate with potassium sulfate.
It is used to purify water (H2O). It is also used in deodorants. It is an antiseptic. It had several uses in the past, such as in dying clothes. It is used to grow big crystals.