Al2SO4318H2O
Al2SO4318H2O refers to a specific hydrated form of aluminum sulfate. Aluminum sulfate is an inorganic salt with the chemical formula Al2(SO4)3. When it crystallizes from aqueous solutions, it often incorporates water molecules into its structure, forming hydrates. The designation "18H2O" indicates that for every formula unit of aluminum sulfate, there are 18 molecules of water associated with it.
This particular hydrate, aluminum sulfate octadecahydrate, is a crystalline solid. While aluminum sulfate is commonly encountered