Acid-base reaction
Vanadium pentoxide is highly acidic and not very alkaline. It can be dissolved in acid to form the corresponding yellow metavanadate radical. It can precipitate into metavanadate at around PH2, and can also be dissolved in alkali to form metavanadate solution.

The positive pentavalent vanadium in vanadium pentoxide can be reduced to obtain VIV, blue VO(H2O)52+ vanadium oxygen ion in an acidic medium. Using hydrochloric acid and hydrobromic acid as reducing agents, the oxidation product is the corresponding halogen element.