Peroxydisulfuric acid
Peroxydisulfuric acid is the inorganic compound with the chemical formula H2S2O8. Also called Marshall's acid after its inventor Professor Hugh Marshall, it is a sulfur oxoacid. In structural terms it can be written HO3SOOSO3H. It contains sulfur in its +6 oxidation state and a peroxide group. Its salts, commonly known as persulfates, are industrially important as powerful oxidizing agents.Synthesis
The acid is prepared by the reaction of chlorosulfuric acid with hydrogen peroxide:
Another method is the electrolysis of moderately concentrated sulfuric acid with platinum electrodes at high current density and voltage:
