Sodium dihydrogen orthophosphate anhydrous 99% AR Grade AR Purity 99% Cas No: 7558-80-7 Molecular weight 119.98 Molecular formula NaH2PO4 Assay 99.0-101.0% pH (5% solution in water, 25°C) 4.1-4.7 Insoluble matter in water Max 0.05% Nitrogen compound (as N) Max 0.002% Chloride (Cl) Max 0.002% Sulphate (SO4) Max 0.005% Arsenic (As) Max 0.001% Calcium (Ca) Max 0.001% Copper (Cu) Max 0.001% Iron (Fe) Max 0.001% Magnesium (Mg) Max 0.01% Nickel (Ni) Max 0.001% Lead (Pb) Max 0.002%