Chemical Properties
White powder
Physical properties
Colorless cubic crystal; density 6.33 g/cm
3; melts at 1,110°C; vaporizes at 1,748°C; vapor pressure 5 torr at 1,231°C; moderately soluble in water, 4.35 g/100mL at 25°C; soluble in hydrofluoric and other mineral acids; practically insoluble in alcohol and liquid ammonia.
Uses
Cadmium fluoride is used in phosphors, glass and nuclear reactor controls. It is also used in high-temperature lubricants and to start crystals for lasers. It is used in oxygen-sensitive applications such as the production of metallic alloys and it is also used in limited medical treatment protocols. In addition, it can be used in synthetic organic chemistry.
Uses
Manufacture of phosphors, glass; in nuclear reactor controls.
Definition
Available as pure crystals, 99.89%, d 6.6, mp approx-
imately 1110C, soluble in water and acids, insoluble
in alkalies.
Preparation
Cadmium fluoride is prepared by the reaction of gaseous fluorine or hydrogen fluoride with cadmium metal or its salt, such as chloride, oxide or sulfide:
Cd + F
2 → CdF
2Cd + 2HF → CdF
2 + H
2CdO + 2HF → CdF
2 + H
2O
It also may be obtained by dissolving cadmium carbonate in 40% hydrofluoric acid solution, evaporating the solution and drying in vacuum at 150°C:
CdCO
3 + 2HF → CdF
2 + H
2O + CO
2It also may be prepared by mixing cadmium chloride and ammonium fluoride solutions, followed by crystallization.
Safety Profile
Confirmed human
carcinogen. Poison by subcutaneous route.
Violent reaction with K. When heated to
decomposition it emits very toxic fumes of
Cd and F-. See also FLUORIDES and
CADMIUM COMPOUNDS.
Purification Methods
Crystallise it by dissolving it in hot water (25mL/g at room temperature) at 60o, filtering, then cooling. [Kwasnik in Handbook of Preparative Inorganic Chemistry (Ed. Brauer) Academic Press Vol I p 243 1963.]
