Difference between revisions of "Vanadium pentoxide"

Revision as of 16:06, 6 July 2017

Vanadium pentoxide

Lab grade V2O5
Names
IUPAC name Divanadium pentaoxide
Other names Vanadia Vanadic anhydride Vanadium(V) oxide
Properties
Chemical formula	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)
Solubility in water	0.08 g/100 ml (20 °C)
Solubility	Soluble in conc. acids, alkali Insoluble in organic solvents
Vapor pressure	~0
Hazards
Safety data sheet	Sigma-Aldrich
Flash point	Non-flammable
Lethal dose or concentration (LD, LC):
LD50 (Median dose)	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 + 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

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 4-11mg/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.

References

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

Relevant Sciencemadness threads

• How to convert ferrovanadium (82%) in vanadium pentoxide