.Chemical name:Disodium Dihydrogen Pyrophosphate, Sodium Acid Pyrophosphate
2.M. F.: Na2H2P2O7
3.M. W. : 221.94
4.Physical properties: Monoclinic, white crystalline powder. Density 1.86. Practically insoluble in alcohol, soluble in water. Hydrolyzes to orthophosphate on heating in acid medium. Hygroscopic, forms hexahydrate in damp air. Decomposes to metaphosphate at above 220
5.Quality standard:( FCC V, GB25567-2010)
Name of index | FCC-V | GB25567-2010 |
Content (as counted by Na2H2P2O7) ≥ % | 93.0-100.5 | 93.0-100.5 |
Water Insoluble% ≤% | 1.0 | 1.0 |
PH (1% aqueous solution) | - | 3.5-4.5 |
Arsenic(As), ppm, ≤ | 3 | 3 |
Heavy Metals (as Pb), ppm, ≤ | 20 | 10 |
Fluoride(F), ppm, ≤ | 50 | 50 |
Pb ppm, ≤ | 2 | 2 |
