Reference Table for Polyphosphates       Chemical Syn. Formula %PO4 %P2O5 pH of 1% solution  Solubility* Sodium Hexametaphosphate SHMP (NaPO3)n  Na2O 91 65 7.0 High Sodium Acid pyrophosphate SAPP Na2P2O7   60 4.3 13 Tetrapotassium pyrophosphate TKPP K4P2O7 56 52     Tetrasodium pyro phosphate TSSP Na4P2O7 68.5 53 10.2 6 Na4P2O7(10H2O ) 41 31     Sodium Tripolyphosphate STPP 4(Na3+12H2O)NaOH 77 56 9.8 13+ *Solubility @ 25 degrees C, per 100 grams saturated solution.