Vanadium(V) oxide also known as vanadium pentoxide or vanadia is the inorganic compound with the formula V2O5. It is one of several oxides of vanadium.
Vanadium pentoxide will yield oxygen and turns into oxides of lower states and finally the pure metal when heated at high temperature.
- V2O5 → VO2 → V2O3 → VO → V
The reaction is reversible.
Vanadium pentoxide will not be reduced to its respective salts if reacted with a strong acid, instead it will generate oxovanadium cations:
- V2O5 + 6HCl + 7H2O → 2[VO(H2O)5]2+ + 4Cl− + Cl2
- V2O5 + 2 HNO3 → 2 VO2(NO3) + H2O
Reaction with thionyl chloride generates vanadium oxychloride:
- V2O5 + 3 SOCl2 → 2 VOCl3 + 3 SO2
Vanadium pentoxide is a brown-yellow compound, slightly soluble in water, where it gives yellow colored solution.
Thermal decomposition of ammonium metavanadate at 200 °C will give pure vanadium pentoxide:
- 2 NH4VO3 → V2O5 + 2 NH3 + H2O
- Vanadium oxides
- Sulfur trioxide and sulfuric acid generation
- Maleic and phthalic anhydride synthesis
- Vanadium redox battery
Vanadium pentoxide exhibits modest toxicity to humans, with an LD50 of about 470 mg/kg. The greater hazard is with inhalation of the dust, where the LD50 ranges from 4-11mg/kg for a 2 week exposure.
Vanadium pentoxide should be stored in closed containers, away from any acidic vapors.
Vanadium pentoxide should not be released in the environment in large quantities.