Physical Properties
Physical state at 20°C : Solid
Colour : White crystalline
Odour : Odorless
pH value ................. 9.2
Melting point ........... 62 °C
Boiling point ............ 320°C
Density .................... 1.73 g/cm3
Solubility in water .... completely soluble (39 g/l at 20 °C)
Specifications
Appearance : A white crystalline powder
Assay (acidimetric) ................ 99.5 - 103%
Identity ................................... Passes test
Clarity of solution ................... Passes test
Insoluble matter ..................... Max 0.005%
pH (0.01 M solution; 25°C) .... 9.15 - 9.20
pH (4% solution in water) ...... 9.0 - 9.6
Chloride (Cl) .......................... Max 0.0007%
Phosphate (PO4) ................... Max 0.001%
Sulphate (SO4) ...................... Max 0.005%
Heavy metal (as Pb) .............. Max 0.001%
Arsenic (As) ........................... Max 0.0005%
Calcium (Ca) ......................... Max 0.005%
Copper (Cu) .......................... Max 0.0005%
Iron (Fe) ................................ Max 0.0005%
Ammonium (NH4) ................. Max 0.001%
Lead (Pb) .............................. Max 0.0005%
