Tungstic acid refers to hydrated forms of tungsten trioxide, WO3.
Molecular species akin to sulfuric acid, i.e. (HO)2WO2 are not observed.
The solid-state structure of WO3·H2O consists of layers of octahedrally coordinated WO5(H2O) units where 4 vertices are shared.
It may also be prepared from the reaction between hydrogen carbonate and sodium tungstate.
It can also be obtained from pure tungsten by reaction with hydrogen peroxide.