Vanadium(V) oxide
Names | |
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IUPAC name
Divanadium pentaoxide
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Other names
Vanadium pentoxide
Vanadic anhydride Divanadium pentoxide | |
Identifiers | |
3D model (
JSmol ) |
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ChEBI | |
ChemSpider | |
ECHA InfoCard
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100.013.855 |
EC Number |
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KEGG | |
PubChem CID
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RTECS number
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UNII | |
UN number | 2862 |
CompTox Dashboard (EPA)
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Properties[3] | |
V2O5 | |
Molar mass | 181.8800 g/mol |
Appearance | Yellow solid |
Density | 3.35 g/cm3[1] |
Melting point | 681 °C (1,258 °F; 954 K)[1] |
Boiling point | 1,750 °C (3,180 °F; 2,020 K)[1] (decomposes) |
0.7 g/L (20 °C)[1] | |
+128.0·10−6 cm3/mol[2] | |
Structure[4] | |
Orthorhombic | |
Pmmn, No. 59 | |
a = 1151 pm, b = 355.9 pm, c = 437.1 pm
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Distorted trigonal bipyramidal (V) | |
Thermochemistry[5] | |
Heat capacity (C)
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127.7 J/(mol·K) |
Std molar
entropy (S⦵298) |
131.0 J/(mol·K) |
Std enthalpy of (ΔfH⦵298)formation |
-1550.6 kJ/mol |
Gibbs free energy (ΔfG⦵)
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-1419.5 kJ/mol |
Hazards | |
GHS labelling: | |
Danger | |
H302, H332, H335, H341, H361, H372, H411 | |
NFPA 704 (fire diamond) | |
Flash point | Non-flammable |
Lethal dose or concentration (LD, LC): | |
LD50 (median dose)
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10 mg/kg (rat, oral) 23 mg/kg (mouse, oral)[7] |
LCLo (lowest published)
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500 mg/m3 (cat, 23 min) 70 mg/m3 (rat, 2 hr)[7] |
NIOSH (US health exposure limits): | |
PEL (Permissible)
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C 0.5 mg V2O5/m3 (resp) (solid)[6]
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Safety data sheet (SDS) | ICSC 0596 |
Related compounds | |
Other anions
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Vanadium oxytrichloride |
Other cations
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Tantalum(V) oxide
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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).
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Vanadium(V) oxide (vanadia) is the
The mineral form of this compound, shcherbinaite, is extremely rare, almost always found among
Chemical properties
Reduction to lower oxides
Upon heating a mixture of vanadium(V) oxide and vanadium(III) oxide, comproportionation occurs to give vanadium(IV) oxide, as a deep-blue solid:[9]
- V2O5 + V2O3 → 4 VO2
The reduction can also be effected by oxalic acid, carbon monoxide, and sulfur dioxide. Further reduction using hydrogen or excess CO can lead to complex mixtures of oxides such as V4O7 and V5O9 before black V2O3 is reached.
Acid-base reactions
V2O5 is an
- V2O5 + 2 HNO3 → 2 VO2(NO3) + H2O
It also reacts with strong
Upon treatment with
- V2O5 + 3 SOCl2 → 2 VOCl3 + 3 SO2
Other redox reactions
Hydrochloric acid and hydrobromic acid are oxidised to the corresponding halogen, e.g.,
- V2O5 + 6HCl + 7H2O → 2[VO(H2O)5]2+ + 4Cl− + Cl2
Vanadates or vanadyl compounds in acid solution are reduced by zinc amalgam through the colourful pathway:
The ions are all hydrated to varying degrees.
Preparation
Technical grade V2O5 is produced as a black powder used for the production of vanadium metal and ferrovanadium.[10] A vanadium ore or vanadium-rich residue is treated with sodium carbonate and an ammonium salt to produce sodium metavanadate, NaVO3. This material is then acidified to pH 2–3 using H2SO4 to yield a precipitate of "red cake" (see above). The red cake is then melted at 690 °C to produce the crude V2O5.
Vanadium(V) oxide is produced when vanadium metal is heated with excess oxygen, but this product is contaminated with other, lower oxides. A more satisfactory laboratory preparation involves the decomposition of ammonium metavanadate at 500–550 °C:[13]
- 2 NH4VO3 → V2O5 + 2 NH3 + H2O
Uses
Ferrovanadium production
In terms of quantity, the dominant use for vanadium(V) oxide is in the production of
Sulfuric acid production
Another important use of vanadium(V) oxide is in the manufacture of
- 2 SO2 + O2 ⇌ 2 SO3
The discovery of this simple reaction, for which V2O5 is the most effective catalyst, allowed sulfuric acid to become the cheap commodity chemical it is today. The reaction is performed between 400 and 620 °C; below 400 °C the V2O5 is inactive as a catalyst, and above 620 °C it begins to break down. Since it is known that V2O5 can be reduced to VO2 by SO2, one likely catalytic cycle is as follows:
- SO2 + V2O5 → SO3 + 2VO2
followed by
- 2VO2 +½O2 → V2O5
It is also used as catalyst in the
Other oxidations
Maleic anhydride is produced by the V2O5-catalysed oxidation of butane with air:
- C4H10 + 4 O2 → C2H2(CO)2O + 8 H2O
Maleic anhydride is used for the production of polyester resins and alkyd resins.[15]
- C6H4(CH3)2 + 3 O2 → C6H4(CO)2O + 3 H2O
The equation for the vanadium oxide-catalysed oxidation of naphthalene to phthalic anhydride:[16]
- C10H8 + 4½ O2 → C6H4(CO)2O + 2CO2 + 2H2O
Phthalic anhydride is a precursor to
A variety of other industrial compounds are produced similarly, including adipic acid, acrylic acid, oxalic acid, and anthraquinone.[8]
Other applications
Due to its high coefficient of
Vanadium redox batteries are a type of flow battery used for energy storage, including large power facilities such as wind farms.[17] Vanadium oxide is also used as a cathode in lithium ion batteries.[18]
Biological activity
Vanadium(V) oxide exhibits very modest acute toxicity to humans, with an
References
- ^ a b c d Haynes, p. 4.94
- ^ Haynes, p. 4.131
- ISBN 0-8493-0462-8..
- .
- ^ Haynes, p. 5.41
- ^ a b NIOSH Pocket Guide to Chemical Hazards. "#0653". National Institute for Occupational Safety and Health (NIOSH).
- ^ a b "Vanadium dust". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
- ^ ISBN 3-527-30673-0.
- ^ Brauer, p. 1267
- ^ ISBN 978-0-08-022057-4..
- ^ Brauer, p. 1264
- ^ "The oxidation states of vanadium". RSC Education. Retrieved 2019-10-04.
- ^ Brauer, p. 1269
- ISBN 978-0-470-63885-9.
- ^ Tedder, J. M.; Nechvatal, A.; Tubb, A. H., eds. (1975), Basic Organic Chemistry: Part 5, Industrial Products, Chichester, UK: John Wiley & Sons.
- ^ Conant, James; Blatt, Albert (1959). The Chemistry of Organic Compounds (5th ed.). New York, New York: The Macmillan Company. p. 511.
- ^ REDT Energy Storage. "Using VRFB for Renewable applications". Archived from the original on 2014-02-01. Retrieved 2014-01-21.
- .
Cited sources
- Brauer, G. (1963). "Vanadium, Niobium, Tantalum". In Brauer, G. (ed.). Handbook of Preparative Inorganic Chemistry, 2nd Ed. NY: Academic Press.
- Haynes, William M., ed. (2016). ISBN 978-1-4987-5429-3.
Further reading
- "Vanadium Pentoxide", Cobalt in Hard Metals and Cobalt Sulfate, Gallium Arsenide, Indium Phosphide and Vanadium Pentoxide (PDF), IARC Monographs on the Evaluation of Carcinogenic Risks to Humans 86, Lyon, France: International Agency for Research on Cancer, 2006, pp. 227–92, ISBN 92-832-1286-X.
- Vaidhyanathan, B.; Balaji, K.; Rao, K. J. (1998), "Microwave-Assisted Solid-State Synthesis of Oxide Ion Conducting Stabilized Bismuth Vanadate Phases", Chem. Mater., 10 (11): 3400–4, .
External links
- International Chemical Safety Card 0596
- NIOSH Pocket Guide to Chemical Hazards. "#0653". National Institute for Occupational Safety and Health (NIOSH).
- NIOSH Pocket Guide to Chemical Hazards. "#0654". National Institute for Occupational Safety and Health (NIOSH).
- Vanadium Pentoxide and other Inorganic Vanadium Compounds (Concise International Chemical Assessment Document 29)
- Environmental Health Criteria 81: Vanadium
- IPCS Health and Safety Guide 042: Vanadium and some vanadium salts