CAS: 7722-88-5 Molecular Formula: Na4P2O7 Molecular Weight: 265.90 g/mol Synonym(s): Sodium diphosphate tetrabasic, Tetrasodium pyrophosphate, Sodium pyrophosphate tetrabasic Test Specification pH (1% Solution) 10.2 - 10.6 Bulk Density 0.70 gm/cc min. Loss on Ignite (at 550 Deg. C, 30 mins) 0.5% max. Water Insoluble 0.1% max. Phosphate (as P2O5) 52.5 - 54.0% Assay 95.0 - 100.5% Retained on 20 mesh (850um) 0.5% max. Pass thru 100 mesh (150um) 80.0% min. Fluoride (as F) 10 ppm max. Arsenic (as As) 3 ppm max. Lead (as Pb) 3 ppm max. Cadmium (as Cd) 1 ppm max. Mercury (as Hg) 1 ppm max.