Strontium ions precipitate with soluble sulphate salts. Reactions of barium hydroxide with ammonium salts are strongly endothermic. Products are produced as their ammonium salts. Amines react with nitrous acid to give diazonium salts. Thus, treatment of concentrated solutions of ammonium salts with strong base gives ammonia. Barium sulfate is one of the most insoluble salts of sulfate. Palmitates are the salts and esters of palmitic acid. Radical initiators include potassium persulfate and hydroperoxides in combination with ferrous salts. Such ions are present in all ionic halide salts. When acids reacted with metals they formed salts and hydrogen gas. Bases were substances that reacted with acids to form salts and water. It is formed by combining aqueous solutions of iodide salts and iodine. Mineral sequestration aims to trap carbon in the form of solid carbonate salts. Two types of coagulants (salts and acids) are used commercially. All forms are white, water-soluble salts.