Tungsten Trioxide and Hydrogen Fluoride Reaction
Hydrogen fluoride chemical formula is HF, it is binary compound consisted of F and H. Its solution is hydrofluoric acid which is transparent and sour corrosion liquid with irritation smell. H atom and F atom combination ability is strong which avoid completely ionization of hydrofluoric acid in water. So theoretically low concentration hydrofluoric acid is weak acid. However, it has strong corrosion ability which can etch metal, glass and silica contained material.
Tungsten trioxide has well anti corrosion property, apart from hydrogen fluoride, it cannot react with any other inorganic acid. Tungsten oxide can partially dissolve in hydrofluoric acid, its chemical equation is: WO3+4HF → H2[WO2F4]+H2O