Terbium(III,IV) oxide
Names | |
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IUPAC name
Tetraterbium heptaoxide
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Other names
Terbium(III,IV) oxide,
Terbium peroxide | |
Identifiers | |
3D model (
JSmol ) |
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ECHA InfoCard
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100.031.675 |
PubChem CID
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CompTox Dashboard (EPA)
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Properties | |
Tb4O7 | |
Molar mass | 747.6972 g/mol |
Appearance | Dark brown-black hygroscopic solid. |
Density | 7.3 g/cm3 |
Melting point | Decomposes to Tb2O3 |
Insoluble | |
Hazards | |
Occupational safety and health (OHS/OSH): | |
Main hazards
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Oxidising agent. |
Related compounds | |
Other cations
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Terbium(III) oxide Terbium(IV) oxide |
Related compounds
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Cerium(IV) oxide Praseodymium(III,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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Terbium(III,IV) oxide, occasionally called tetraterbium heptaoxide, has the formula Tb4O7, though some texts refer to it as TbO1.75. There is some debate as to whether it is a discrete compound, or simply one phase in an
Synthesis
Tb4O7 is most often produced by ignition of the oxalate or the sulfate in air.[1] The oxalate (at 1000 °C) is generally preferred, since the sulfate requires a higher temperature, and it produces an almost black product contaminated with Tb6O11 or other oxygen-rich oxides.
Chemical properties
Terbium(III,IV) oxide loses
Tb4O7 reacts with atomic oxygen to produce TbO2, but more convenient preparations are available.[3]
- Tb
4O
7 (s) + 6 HCl (aq) → 2 TbO
2 (s) + 2 TbCl
3 (aq) + 3 H
2O (l)
. Tb4O7 reacts with other hot concentrated acids to produce terbium(III) salts. For example, reaction with sulfuric acid gives terbium(III) sulfate. Terbium oxide reacts slowly with hydrochloric acid to form terbium(III) chloride solution, and elemental chlorine. At ambient temperature, complete dissolution might require a month; in a hot water bath, about a week.
Anhydrous terbium(III) chloride can be produced by the
In the first step, terbium oxide is heated with ammonium chloride to produce the ammonium salt of the pentachloride:- Tb4O7 + 22 NH4Cl → 4 (NH4)2TbCl5 + 7 H2O + 14 NH3
In the second step, the ammonium chloride salt is converted to the trichlorides by heating in a vacuum at 350-400 °C:
- (NH4)2TbCl5 → TbCl3 + 2 HCl + 2 NH3
References
- ISBN 9783540935254.
- .
- ISBN 3-13-103071-2.
- ^ Brauer, G., ed. (1963). Handbook of Preparative Inorganic Chemistry (2nd ed.). New York: Academic Press.
- ^
Meyer, G. (1989). "The Ammonium Chloride Route to Anhydrous Rare Earth Chlorides—The Example of Ycl 3". The Ammonium Chloride Route to Anhydrous Rare Earth Chlorides-The Example of YCl3. Inorganic Syntheses. Vol. 25. pp. 146–150. ISBN 978-0-470-13256-2.
- ISBN 978-3-13-103021-4.
Further reading
- CRC Handbook of Chemistry and Physics (71st ed.). Ann Arbor, Michigan: CRC Press. 1990. ISBN 978-0-8493-0471-2.
- Mellor, J.W. A Comprehensive Treatise on Inorganic and Theoretical Chemistry. London: Longmans, Green & Co. pp. 692–696.