Physical Properties
Yellow amorphous powder; density 5.59 g/cm3; decomposes at 100°C; insoluble in water and most acids; soluble in hydrofluoric acid, caustic alkalies and ammonia solution. Freshly prepared tungstic acid containing a molecule of water of crystallization is moderately soluble in water.
Uses
Tungstic acid is used in preparing tungsten metal and many tungsten compounds. Also, it is a mordant for textiles.
Preparation
Tungstic acid is obtained as an intermediate in the recovery of tungsten from its minerals, scheelite and wolframite (See Tungsten). Also, the tungstic acid may be prepared by heating sodium tungstate with sulfuric acid or hydrochloric acid:
Na2WO4 + 2HCl → H2WO4 + 2NaCl
Na2WO4 + H2SO4 → H2WO4 + Na2SO4
Chemical Properties
light yellow powder
Physical properties
Yellow amorphous powder; density 5.59 g/cm
3; decomposes at 100°C; insoluble in water and most acids; soluble in hydrofluoric acid, caustic alkalies and ammonia solution. Freshly prepared tungstic acid containing a molecule of water of crystallization is moderately soluble in water.
Uses
Tungstic Acid is used as a starting material in the synthesis of polynanocomposite material and polycrystalline ceramics.
Definition
ChEBI: Tungstic acid is a tungsten coordination entity. It is a conjugate acid of a hydrogentungstate.
General Description
Tungstic acid may be prepared by either digesting tungstate of lime or by treating tungsten with hydrochloric acid. 1
Flammability and Explosibility
Not classified
