8696. Sodium Trimetaphosphate

Nomenclature

CAS number: 7785-84-4
Metaphosphoric acid trisodium salt.
Na3O9P3; mol wt 305.89.
Na 22.55%, O 47.07%, P 30.38%.
(NaPO3)3.

Description and references

Prepd by tempering sodium hexametaphosphate at about 500° for 8-12 hrs; by heating Na2HPO4 and NH4NO3 to 320° or by heating NaH2PO4 at 530°: Fleitmann, Henneberg, Ann. 65, 304 (1848); v. Knoore, Z. Anorg. Allg. Chem. 24, 381 (1900); Karbe, Jander, Kolloid-Beih. 54, 35 (1942); Bell, Inorg. Synth. 3, 103 (1950); Lee, Bond, J. Appl. Chem. 18, 345 (1968). Crystal structure of hexahydrate: Caglioti et al., Atti Acad. Italia Rend. 3 [7], 761 (1942), C.A. 40, 6927b (1946); of anhydrate: Ondik, Acta Crystallogr. 18, 226 (1965). Use in detergent processing: Shen, J. Am. Oil Chem. Soc. 45, 510 (1968). Toxicity study: Behrens, Seelkopf, Arch. Exp. Pathol. Pharmakol. 169, 238 (1932). Reviews: see Sodium Metaphosphate.

Derivative

Hexahydrate.

Properties

Efflorescent, triclinic-rhombohedral prisms. d 1.786. mp 53°. Loses water on storage at 20°, becomes definitely anhydr at 100°. d (anhydr) 2.49. One gram dissolves in 4.5 ml water. Insol in alc. LD orally in mice: >100 mg/kg (Behrens, Seelkopf).

Use

In detergent processing.