Lead Persulphate, PbS₂O₈

Lead Persulphate, PbS₂O₈.(?)₃H₂O, is formed in solution by adding lead carbonate to persulphuric acid solution, and is obtained on evaporation in vacuo in ill-defined, deliquescent crystals, very soluble in water. From a solution of lead persulphate alkali precipitates lead hydroxide, which is quickly oxidised to the dioxide. It is noteworthy that this salt, PbS₂O₈, is isomeric with plumbic sulphate, Pb(SO₄)₂.