Dithionous acid

Dithionous acid is a sulfur oxoacid with the chemical formula H2S2O4. It has not been observed experimentally. It is the conjugate base of the dithionite dianion, S2O42-. Dithionite is a well-known reducing agent.

Related compounds

 * Dithionic acid (H2S2O6), another unstable protonated sulfur oxide, derived from dithionate.