Dihydrogenphosphates

Dihydrogenphosphates are a group of chemical compounds that are anions or salts containing the dihydrogenphosphate ion, H2PO4-. This ion is derived from phosphoric acid (H3PO4) by the removal of one proton. Dihydrogenphosphates are often found as the monobasic salt of phosphoric acid. In aqueous solution, the dihydrogenphosphate ion can exist in equilibrium with other phosphate species, including the hydrogenphosphate ion (HPO4^2-) and the phosphate ion (PO4^3-), depending on the pH. The acidity of the dihydrogenphosphate ion means it can act as a weak acid.

Common examples of dihydrogenphosphates include sodium dihydrogenphosphate (NaH2PO4), potassium dihydrogenphosphate (KH2PO4), and calcium dihydrogenphosphate (Ca(H2PO4)2). These salts have a variety of applications. Sodium dihydrogenphosphate, for instance, is used in food processing as a buffering agent, leavening agent, and emulsifier. It is also used in water treatment and as a component in some cleaning products. Potassium dihydrogenphosphate finds use in fertilizers, as a food additive, and in buffer solutions for laboratory experiments. Calcium dihydrogenphosphate is a source of calcium and phosphorus and is used in animal feed and fertilizers. The properties and uses of dihydrogenphosphates are closely linked to their chemical structure and their role in acid-base chemistry.