Vanadate

Often vanadate refers to oxoanions of vanadium, most of which exist in its highest oxidation state of +5.

In this respect vanadium shows similarities to tungstate and molybdate, whereas chromium however has a more limited range of ions.

Dissolution of vanadium pentoxide in strongly basic aqueous solution gives the colourless VO3−4 ion.

On acidification, this solution's colour gradually darkens through orange to red at around pH 7.

Brown hydrated V2O5 precipitates around pH 2, redissolving to form a light yellow solution containing the [VO2(H2O)4]+ ion.