3- .It seems unlikely that free tungstic acids of any of these forms are sable. Further acidification of isopolytungstates gives WO 3 ,2H 2 O, Heteropolytungstates are used to form Wcontaining catalysts by heating. The concentrated ores are fused with NaOH and, after water extraction, WO 3 is precipitated with acid and reduced to the metal with H 2 . The metal is bcc. The metal isused extensively in steel alloys, in electric lamp and heating filaments and in electric contaces.
Tungsten carbides are very hard and are used in cutting tools.
There is little aqueous chemistry except that of complex oxy-anions and some complex halides. Carbonyl and phos-phine derivatives are typical low oxidation state compounds. Complex cyanides are well established. Tungstic acid See tungstates. Tungsten oxides Yellow WO 3 is the final product from heating tungsten or other tungsten oxides in excess oxygen.