Silver orthophosphate, Ag₃PO₄

With solutions of normal or secondary sodium orthophosphate Silver nitrate gives a yellow precipitate of silver orthophosphate, Ag₃PO₄, containing Silver nitrate which cannot be removed by washing. Secondary silver orthophosphate, Ag₂HPO₄, is obtained in white crystals from the solution of the normal orthophosphate in aqueous phosphoric acid. At 170° C. it changes to the pyrophosphate.