Solid-liquid systems crystalline anhydrate

Tungsten (VI) fluoride is a colorless gas that condenses to a colorless liquid at 19.5 and freezes to a crystalline white solid at 2.5°. It fumes in moist air and must be handled under anhydrous conditions. The specific gravity of the liquid is 3.441 at 15°. It may be handled in carefully out-gassed glass systems provided that greases, mercury, and organic materials, as well as water, are absent from the system. 

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