13446-24-7

colorless; monoclinic [CRC10]

Magnesium pyrophosphate has the molecular formula of Mg2P2O7 and the molecular weight of grams per mole. It may be prepared by the solid-state reaction of the dibasic orthophosphate, or alternately by the precipitation of a soluble Mg salt with aqueous pyrophosphoric acid:? 2MgHPO4 (or MgNH4PO4) + heat0Mg2P2O7 +H2O (+NH3)? MgCl2 (aq)+H4P2O7 (aq)0Mg2P2O7 (solid)+2HCl (aq)? In the solution method, the result is the hexahydrate, Mg2P2O7·6H2O. This is a white powder with a CAS number of 13478-16-5 and a molecular weight of 245.4073 g/mol. Its density is 1.71 g/cm³ and it is relatively insoluble in water or ethanol but soluble in acids.