3D model (JSmol)
CompTox Dashboard (EPA)
|Molar mass||305.885 g/mol|
|Appearance||colorless or white crystals|
|Density||2.49 g/cm3 (anhydrous) |
1.786 g/cm3 (hexahydrate)
|Melting point||53 °C (127 °F; 326 K) (hexahydrate, decomposes to anyhdrous)|
|22 g/100 mL|
|Solubility||insoluble in alcohol|
Refractive index (nD)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|what is ?)(|
Sodium trimetaphosphate (also STMP), with formula Na3P3O9, is a metaphosphate of sodium. It has the empirical formula NaPO3. It is the sodium salt of trimetaphosphoric acid. It is a colourless solid that finds specialised applications in food and construction industries. STMP is prepared by heating samples sodium polyphosphate. 
Although drawn with a particular resonance structure, the trianion has D3d symmetry. Hydrolysis of the ring leads to the acyclic sodium triphosphate:
The main reactions of the triphosphate anion is ring-opening by nucleophiles, including amines.