Chemical Properties of Tungsten

       Tungsten is a rare high melting point metal belonging to the VIB group of the sixth period (second long period) of the periodic table.



Tungsten is a silver-white metal that looks like steel. Tungsten has a high melting point, a low vapor pressure, and a low evaporation rate. The chemical properties of tungsten are very stable. It does not react with air and water at room temperature. When it is not heated, any concentration of hydrochloric acid, sulfuric acid, nitric acid, hydrofluoric acid or even aqua regia will not work on tungsten. When the temperature rises to 80°-100 At °C, among the above-mentioned acids, except for hydrofluoric acid, other acids have weak effects on tungsten.



At room temperature, tungsten can be quickly dissolved in the mixed acid of hydrofluoric acid and concentrated nitric acid, but it does not work in alkaline solution. In the presence of air, molten alkali can oxidize tungsten to tungstate. In the presence of oxidants (NaNO3, NaNO2, KClO3, PbO2), the reaction to generate tungstate is more violent. At high temperature, tungsten can combine with chlorine, bromine, iodine, carbon, nitrogen, sulfur, etc., but not with hydrogen.