AVA Chemicals [P] Ltd. Manufactures LR Grade Trisodium Phosphate. AVA Chemicals [P] Ltd. Is an ISO 9001:2000 certified company. The chemical formula of LR Grade Trisodium Phosphate is Na3 PO4 12H2O and the molecular weight is 393.3. It has a white crystals appearance. The assay of this chemical is minimum 99 %. Ph of a 5% Solution of LR Grade Trisodium Phosphate is 11.5 to 12.5. The maximum limit of impurities in percentage is as follows: