What is "tungstic acid"

Tungstic \Tung"stic\, a. (Chem.) Of or pertaining to tungsten; derived from, or resembling, tungsten; wolframic; as, tungstic oxide.

Tungstic acid, an acid of tungsten, H2WO4, analogous to sulphuric and chromic acids.

n. (context chemistry English) the solid hydrated form of tungsten oxide, H₂WO₄; used in textiles, and in yellow glazes

n. an oxyacid of tungsten (often polymeric in nature) formed by neutralizing alkaline tungstate solutions

Tungstic acid refers to hydrated forms of tungsten trioxide, WO. The simplest form, the monohydrate, is WO·HO, the dihydrate WO·2HO is also known. The solid state structure of WO·HO consists of layers of octahedrally coordinated WO(HO) units where 4 vertices are shared. The dihydrate has the same layer structure with the extra HO molecule intercalated between the layers. The monohydrate is a yellow solid and insoluble in water. The classical name for this acid is 'acid of wolfram'.

The acid was discovered for the first time by Carl Wilhelm Scheele in 1781.