Oxoacids of Sulphur

Sulphur forms a number of oxoacids such as H₂SO₃, H₂S₂O₃, H₂S₂O₄, H₂S₂O₅, H₂S_xO₆ (x = 2 to 5), H₂SO₄, H₂S₂O₇, H₂SO₅, H₂S₂O₈.

Some of these acids are unstable and cannot be isolated. They are known in aqueous solution or in the form of their salts.