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 along with all phosphites. Phosphites contain phosphorus in its +3 oxidation state and are therefore reducing agents.

CAS：13517-23-2
中文别名：亚磷酸氢二钠,五水;亚磷酸钠,五水合物;亚磷酸氢二钠;亚磷酸钠,五水;
英文别名：SODIUM PHOSPHITE-5-HYDRATE;
分子式：H11Na2O8P
分子量：216.036
精确质量：215.999
Psa：126.09
Logp：-0.2549

外观与性状：白色结晶固体
稳定性：Stable. Incompatible with strong oxidizing agents.

安全说明：S22