Cadmium fluoride

Chemical properties

White powder

Physical properties

Colorless cubic crystal; density 6.33 g/cm³; 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.

The Uses of Cadmium fluoride

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.

The Uses of Cadmium fluoride

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 + F₂ → CdF₂
Cd + 2HF → CdF₂ + H₂
CdO + 2HF → CdF₂ + H₂O
It also may be obtained by dissolving cadmium carbonate in 40% hydrofluoric acid solution, evaporating the solution and drying in vacuum at 150°C:
CdCO₃ + 2HF → CdF₂ + H₂O + CO₂
It 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.]