Hazard and Precautionary Statements (GHS)

Magnesium Pyrosulfate Chemical Properties,Usage,Production

Description

Magnesium pyrosulfate has the molecular formula of MgS₂O₇ and the molecular weight of 200.4328 g/mol. Almost no data concerning this salt is available either in patents, scientific or technical literature, or in reference books. Since this salt is not stable in water, it must be prepared by a solid-state reaction. One such reaction involves heating ammonium pyrosulfate with the oxide:
MgO+(NH4)2S2O7+heat ? MgS2O7+2H2O+2NH3
It is known that the lower molecular weight alkaline earth pyrosulfates are not very stable in moist air or aqueous solution and hydrolyze to sulfate:
S2O7^2-+H2O ? 2SO4^2-+2H⁺
MgS2O7+H2O?2MgSO4+2H⁺
Magnesium pyrosulfate, once formed, is relatively stable in dry air and can be heated to about 750 °C before it decomposes to the sulfate.