Sulfur oxoacid


The sulfur oxoacids are chemical compounds that contain sulfur, oxygen, and hydrogen. The best known and most important industrially used is sulfuric acid. Sulfur has several oxoacids; however, some of these are known only from their salts. The acids that have been characterised contain a variety of structural features, for example:
AcidFormulaOxidation numberStructureRelated anionsNotes
Sulfuric acidH2SO4+6Sulfate, and hydrogen sulfate commonly known as bisulfate, Best known and industrially significant.
Polysulfuric acids including disulfuric acid or pyrosulfuric acidH2SO4·nSO3+6Disulfate, and trisulfate, Pure disulfuric acid melts at 36 °C. Present in fuming sulfuric acid, oleum. Examples known for n = 1 and n = 2.
Peroxymonosulfuric acidH2SO5+6Peroxymonosulfate, "Caro's acid", a solid melting at 45 °C
Peroxydisulfuric acidH2S2O8+6Peroxydisulfate, "Marshall's acid", a solid melting at 65 °C.
Dithionic acidH2S2O6+5Dithionate, Not isolated in pure form, only concentrated solutions have been prepared
Thiosulfuric acidH2S2O30, +4 Thiosulfate,
Hydrogenthiosulfate 		Aqueous solutions decompose.
Disulfurous acid or pyrosulfurous acidH2S2O5+5, +3 Disulfite commonly known as metabisulfite, Not known.
Sulfurous acidH2SO3+4Bisulfite, and sulfite, Not known.
Dithionous acidH2S2O4+3Dithionite, Not known.
Sulfoxylic acidH2SO2+2Sulfoxylate, Free acid not known
Polythionic acidH2SxO60, +5 Polythionates,. Example trithionate, tetrathionate, pentathionate, hexathionate, heptathionate, octathionate, nonathionate, decathionate, undecathionate, dodecathionate, tridecathionate, and tetradecathionate.Examples known with x = 3, 4, 5, 6, 7, 8, 10, 12, 14.
Thiosulfurous acidH2S2O2−1, +3 ThiosulfitesNot known
DihydroxydisulfaneH2S2O2+1Acid known