Vanadium pentoxide

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Vanadium pentoxide
Vanadium pentoxide sample.jpg
Lab grade V2O5
Names
IUPAC name
Divanadium pentaoxide
Other names
Vanadia
Vanadic anhydride
Vanadium(V) oxide
Properties
V2O5
Molar mass 181.8800 g/mol
Appearance Yellow solid
Odor Odorless
Density 3.357 g/cm3
Melting point 690 °C (1,274 °F; 963 K)
Boiling point 1,750 °C (3,180 °F; 2,020 K) (decomposition)
0.08 g/100 ml (20 °C)
Solubility Soluble in conc. acids, alkali
Insoluble in organic solvents
Vapor pressure ~0 mmHg
Hazards
Safety data sheet Sigma-Aldrich
Flash point Non-flammable
Lethal dose or concentration (LD, LC):
10 mg/kg (rat, oral)
23 mg/kg (mouse, oral)
Related compounds
Related compounds
Vanadium oxychloride
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

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.

Properties

Chemical

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 + 6 HCl + 7H2O → 2 [VO(H2O)5]2+ + 4 Cl + Cl2
V2O5 + 2 HNO3 → 2 VO2(NO3) + H2O

Reaction with thionyl chloride generates vanadium oxychloride:

V2O5 + 3 SOCl2 → 2 VOCl3 + 3 SO2

Solid V2O5 is reduced by oxalic acid, carbon monoxide, and sulfur dioxide to give vanadium(IV) oxide, VO2 as a deep-blue solid.

Sodium metavanadate can be made by reacting vanadium(V) oxide with hot sodium carbonate. This can then be reacted with ammonium chloride to form the less soluble ammonium metavanadate[1].

Physical

Vanadium pentoxide is a brown-yellow compound, slightly soluble in water, where it gives yellow colored solution.

Availability

Vanadium pentoxide is sold by certain ceramic pigment companies. US pigment sells 1 pound at $30, and Seattle Pottery Supply sells it for $24 per pound.

Preparation

Thermal decomposition of ammonium metavanadate at 200 °C will give pure vanadium pentoxide:

2 NH4VO3 → V2O5 + 2 NH3 + H2O

Projects

  • Vanadium oxides
  • Sulfur trioxide and sulfuric acid generation
  • Maleic and phthalic anhydride synthesis
  • Vanadium redox battery

Handling

Safety

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 4-11 mg/kg for a 2 week exposure.

Storage

Vanadium pentoxide should be stored in closed containers, away from any acidic vapors.

Disposal

Vanadium pentoxide should not be released in the environment in large quantities. Recycle it or take it to waste disposal centers.

References

  1. https://www.youtube.com/watch?v=KUHO1DKKyG4

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