976. Barium Hexafluorosilicate

Nomenclature

CAS number: 17125-80-3
Barium fluosilicate; barium silicofluoride.
BaF6Si; mol wt 279.40.
Ba 49.15%, F 40.80%, Si 10.05%.
BaSiF6.

Description and references

Prepd from BaCl2 and H2SiF6: Truchot, Compt. Rend. 98, 821 (1884); Hoffmann, Gutowsky, Inorg. Synth. 4, 145 (1953).

Properties

Orthorhombic needles. d421 4.29. Dec at 300°. Heat of formation (solid) 677.42 kcal/mol. Soly in water (g/100 ml H2O): 0.015 (0°); 0.0235 (25°); 0.091 (100°). Prolonged contact with water produces hydrolysis which is much accelerated by the presence of alkali. Slightly sol in dil acids; sol in ammonium chloride soln; practically insol in alc.

Caution

Highly toxic, especially when brought into soln by alkali.

Use

Prepn of silicon tetrafluoride; as pesticide.