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Vanadium(V) oxide

Vanadium(V) oxide
Vanadium pentoxide monolayer
Vanadium(V) oxide
Names
IUPAC name
Divanadium pentaoxide
Other names
Vanadium pentoxide
Vanadic anhydride
Divanadium pentoxide
Identifiers
3D model (Jmol)
ChEBI
ChemSpider
ECHA InfoCard 100.013.855
EC Number 215-239-8
KEGG
PubChem CID
RTECS number YW2450000
UN number 2862
Properties
V2O5
Molar mass 181.8800 g/mol
Appearance Yellow solid
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) (decomposes)
0.8 g/L (20 °C)
+128.0·10−6 cm3/mol
Structure
Orthorhombic
Pmmn, No. 59
a = 1151 pm, b = 355.9 pm, c = 437.1 pm
Distorted trigonal bipyramidal (V)
Hazards
Safety data sheet ICSC 0596
GHS pictograms Muta. 2; Repr. 2; STOT RE 1Acute Tox.4; STOT SE 3Aquatic Chronic 2
GHS signal word DANGER
H341, H361, H372, H332, H302, H335, H411
Muta. Cat. 3
Repr. Cat. 3
Toxic (T)
Harmful (Xn)
Irritant (Xi)
Dangerous for the environment (N)
R-phrases R20/22, R37, R48/23, R51/53, R63, R68
S-phrases (S1/2), S36/37, S38, S45, S61
NFPA 704
Flammability code 0: Will not burn. E.g., water Health code 3: Short exposure could cause serious temporary or residual injury. E.g., chlorine gas Reactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g., liquid nitrogen Special hazards (white): no codeNFPA 704 four-colored diamond
Flash point Non-flammable
Lethal dose or concentration (LD, LC):
LD50 (median dose)
10 mg/kg (rat, oral)
23 mg/kg (mouse, oral)
500 mg/m3 (cat, 23 min)
70 mg/m3 (rat, 2 hr)
US health exposure limits (NIOSH):
PEL (Permissible)
C 0.5 mg V2O5/m3 (resp) (solid)


C 0.1 mg V2O5/m3 (fume)

Related compounds
Other anions
Vanadium oxytrichloride
Other cations
Niobium(V) oxide
Tantalum(V) oxide
Related vanadium oxides
Vanadium(II) oxide
Vanadium(III) oxide
Vanadium(IV) oxide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YesYN ?)
Infobox references


C 0.1 mg V2O5/m3 (fume)

Vanadium(V) oxide (vanadia) is the inorganic compound with the formula V2O5. Commonly known as vanadium pentoxide, it is a brown/yellow solid, although when freshly precipitated from aqueous solution, its colour is deep orange. Because of its high oxidation state, it is both an amphoteric oxide and an oxidizing agent. From the industrial perspective, it is the most important compound of vanadium, being principal precursor to alloys of vanadium and is a widely used industrial catalyst.

The mineral form of this compound, shcherbinaite, is extremely rare, almost always found among fumaroles. A mineral trihydrate, V2O5·3H2O, is also known under the name of navajoite.

Upon heating, it reversibly loses oxygen, successively forming V2O4, V2O3, VO, and metallic vanadium.

Unlike most metal oxides, it dissolves slightly in water to give a pale yellow, acidic solution. When this compound is formed by V2O5 it is an amphoteric oxide. Thus V2O5 reacts with strong non-reducing acids to form solutions containing the pale yellow salts containing dioxovanadium(V) centers:

It also reacts with strong alkali to form polyoxovanadates, which have a complex structure that depends on pH. If excess aqueous sodium hydroxide is used, the product is a colourless salt, sodium orthovanadate, Na3VO4. If acid is slowly added to a solution of Na3VO4, the colour gradually deepens through orange to red before brown hydrated V2O5 precipitates around pH 2. These solutions contain mainly the ions HVO42− and V2O74− between pH 9 and pH 13, but below pH 9 more exotic species such as V4O124− and HV10O285− (decavanadate) predominate.


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