Alums: Properties and Uses Assignment Point
The alums are a class of chemical compounds. Alums are double sulfate salts, with the general formula AM(SO 4) 2 ·12H 2 O, where A is a monovalent cation such as potassium or ammonium and M is a trivalent metal ion such as aluminum or chromium(III). By itself, "alum" often refers to potassium alum, the hydrated potassium aluminum sulfate with the formula KAl(SO 4) 2 ·12H 2 O.