A persulfate (sometimes known as peroxysulfate or peroxodisulfate) is a compound containing the anions or . The anion contains one peroxide group per sulfur center, whereas in , the peroxide group bridges the sulfur atoms. In both cases, sulfur adopts the normal tetrahedral geometry typical for the S(VI) oxidation state. These salts are strong oxidizers. Ions Peroxomonosulfate ion, Peroxydisulfate Acids Peroxymonosulfuric acid (Caro's acid), H2SO5 Peroxydisulfuric acid, H2S2O8 Example salts Sodium peroxomonosulfate, Na2SO5 Potassium peroxymonosulfate, KHSO5 Sodium persulfate (sodium peroxydisulfate), Na2S2O8 Ammonium persulfate (ammonium peroxydisulfate), (NH4)2S2O8 Potassium persulfate (potassium peroxydisulfate), K2S2O8 References Sulfur oxyanions Preservatives