Tags: Chemical Compound, Chemical Substance.
Disodium hydrogen phosphite is the chemical compound Na2HPO3 which is commonly encountered as the pentahydrate. It is a salt of phosphorous acid HP(O)(OH)2 and contains the anion HPO32−. Its common name suggests that it contains an acidic hydrogen atom as in sodium hydrogen carbonate. However this is misleading as the hydrogen atom is bonded to phosphorus rather than oxygen. It is toxic[citation needed] along with all phosphites.
