Sodium hyperoxide
Crystal structure | |||||||||||||
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__ Na + __ O 2 - | |||||||||||||
General | |||||||||||||
Surname | Sodium hyperoxide | ||||||||||||
other names |
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Ratio formula | NaO 2 | ||||||||||||
Brief description |
easily decomposable yellow solid |
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properties | |||||||||||||
Molar mass | 54.99 g mol −1 | ||||||||||||
Physical state |
firmly |
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density |
2.2 g cm −3 |
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Melting point |
552 ° C (decomposition) |
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safety instructions | |||||||||||||
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As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . |
Sodium hyperoxide is a chemical compound with the formula NaO 2 from the group of hyperoxides .
Representation and occurrence
It is formed when sodium peroxide reacts with oxygen at high temperatures and pressures (e.g. when meteorites enter the earth's atmosphere) and occurs in some minerals .
properties
Sodium hyperoxide decomposes on contact with water ( hydrolysis ) to sodium hydroxide and oxygen and / or hydrogen peroxide :
It occurs in three crystal structures (trimorphic): below −77 ° C in a marcasite structure (similar to FeS 2 ), between −77 ° C and −50 ° C in a pyrite structure and above −50 ° C similar to common salt ( NaCl ).
The standard enthalpy of formation of sodium hyperoxide is ΔH f 0 = -260 kJ / mol.
Future applications
Sodium hyperoxide is currently the subject of battery research . The development of modern metal-air batteries shows great potential in terms of stability, charging and discharging efficiency.
See also
Web links
- uni-Kiel: Alkali Metals (PDF file; 2.46 MB)
Individual evidence
- ↑ Entry on sodium oxides. In: Römpp Online . Georg Thieme Verlag, accessed on September 29, 2014.
- ↑ Sodium Hyperoxide at webelements.com
- ^ A b A. F. Holleman , E. Wiberg , N. Wiberg : Textbook of Inorganic Chemistry . 101st edition. Walter de Gruyter, Berlin 1995, ISBN 3-11-012641-9 , p. 1176.
- ↑ This substance has either not yet been classified with regard to its hazardousness or a reliable and citable source has not yet been found.
- ↑ a b Stephen E. Stephanou et al .: Sodium superoxide . In: JC Bailar, Jr. (Ed.): Inorganic Syntheses . tape 4 . McGraw-Hill, Inc., 1953, pp. 82-85 (English).
- ↑ P. Hartmann et al .: A rechargeable room-temperature sodium superoxide (NaO 2 ) battery , Nature Materials 12, 2013, pp. 228-232, doi : 10.1038 / nmat3486 .