PreLab Q3. What is the molar mass of Alum. Show calculation (Hint, the mass will include the 12H2O molecules) "Alum" is a general term that usually refers to chemical compounds containing a monovalent and atrivalent cation, and two sulfate groups. The most common alum is potassium aluminum sulfate dodecahydrate, 2KAl2(SO4)212H2O. Alum is used as a styptic, in pickling of foods, in water treatment, Erc. In this lab you will make alum from aluminum metal, potassium hydroxide and sulfuric acid, and then purify the product via crystallization