Disodium Hydrogen Phosphate (Na2HPO4) is a sodium salt of phosphoric acid. It is a white powder that is highly hygroscopic and water soluble. It is therefore used commercially as an anti-caking additive in powdered products. It is also known as disodium hydrogen orthophosphate, sodium hydrogen phosphate or sodium phosphate dibasic. It is commercially available in both the hydrated and anhydrous forms. pH of disodium hydrogen phosphate water solution is between 8.0 and 11.0.