Alum (Alum) is a hydrated double salt group in the form of crystals and is isomorphic in nature. These alum crystals are quite soluble in water, and their solubility varies depending on the type of metal and temperature.
Alum is one of the chemical compounds made from water molecules and two types of salt, one of which is usually Al2 (SO4) 3. Potassium alum, also commonly known as alum, has a formula called K2SO4.Al2 (SO4) 3.24H2O. [1] Potassium alum is the most important type of alum. Potassium alum is a colorless compound and has an octahedral or cube crystalline form when potassium sulfate and aluminum sulfate are both dissolved and cooled. The potassium alum solution is acidic. Potassium alum is very soluble in hot water. When crystalline potassium alum is heated chemical separation occurs, and part of the dehydrated salt is dissolved