hydrogenfluorine

Hydrogen fluoride, chemical formula HF, is a diatomic molecule consisting of hydrogen and fluorine. The name hydrogenfluorine appears in some older sources, but HF is the standard designation. In aqueous solution HF is hydrofluoric acid. The compound is highly corrosive and toxic, and it forms a variety of fluoride salts with metals.

HF is a colorless gas at room temperature, with a boiling point of 19.5°C, so it readily exists as a gas at ambient conditions or as a liquid under modest cooling. It is miscible with water and forms a strong hydrogen-bond network; in pure state it forms polymeric chains. HF readily attacks siliceous materials, especially glass, forming silicon tetrafluoride or dissolving silica.

Industrially HF is produced by treating calcium fluoride with sulfuric acid: CaF2 + H2SO4 → 2 HF + CaSO4. It is stored and transported in corrosion-resistant equipment, commonly using fluoropolymers rather than glass or most metals. Adequate ventilation and protective equipment are required during handling.

Hydrogen fluoride is a key building block for fluorinated compounds. It is used to manufacture fluoropolymers, refrigerants, solvents, and pharmaceuticals, and serves in glass etching and semiconductor processing (where it removes silicon dioxide). In earlier times, HF was employed as a catalyst in certain alkylation processes for gasoline production.

HF is exceptionally hazardous. Inhalation or skin contact can cause deep tissue burns and systemic fluoride poisoning. Treatment involves prompt washing and, in medical settings, administration of fluoride antidotes such as calcium compounds. Handling should occur under a fume hood with appropriate PPE and corrosion-resistant containment.