Caesium fluorides

Evaporation of a solution of caesium carbonate in hydrofluoric acid yields the primary Caesium fluorides, CsF,HF. When heated, this substance is converted into the normal fluoride, CsF, which crystallizes in cubes, melts at 684° C., and boils at 1251° C. Its vapour-pressure in atmospheres corresponds with the expression

log p = -34700/4.57T+4.982.

The anhydrous fluoride yields two very deliquescent hydrates, CsF,1.5H₂O, and 3CsF,2H₂O. The heat of solution of the anhydrous salt is 8.37 Cal.