Lithium carbide
Structural formula | |||||||||||||||||||
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General | |||||||||||||||||||
Surname | Lithium carbide | ||||||||||||||||||
other names |
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Molecular formula | Li 2 C 2 | ||||||||||||||||||
Brief description |
translucent, white to gray crystalline solid |
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properties | |||||||||||||||||||
Molar mass | 37.90 g mol −1 | ||||||||||||||||||
Physical state |
firmly |
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density |
1.3 g cm −3 |
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Melting point |
decomposition |
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solubility |
almost insoluble in organic solvents |
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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 . |
Lithium carbide is a chemical compound from the group of carbides .
Extraction and presentation
Lithium carbide can be obtained by reacting lithium with carbon .
At higher pressures, LiC 2 or LiC 4 is formed instead of lithium carbide (Li 2 C 2 ) .
If lithium carbonate is heated in an electric furnace with an excess of carbon , lithium carbide is also formed.
In diethyl ether , lithium carbide can be produced by the reaction of 1,2-dichloroethane with phenyllithium , producing a thick, colorless precipitate of lithium carbide and monolithium acetylide.
properties
Physical Properties
Lithium carbide is a crystalline solid that has an orthorhombic crystal system with the space group Immm (space group no. 71) and the lattice parameters a = 365.5 pm , b = 544.0 pm and c = 483.3 pm. It is isotypic to rubidium peroxide (Rb 2 O 2 ) and cesium peroxide (Cs 2 O 2 ).
The standard enthalpy of formation is −59.5 kJ / mol.
Chemical properties
Lithium carbide reacts with water to form ethyne .
Lithium carbide also decomposes in molten potassium hydroxide , although it is only slowly attacked by concentrated acids.
Individual evidence
- ^ A b R. Abegg, F. Auerbach, I. Koppel: "Handbuch der inorganic Chemie", Verlag S. Hirzel, 1908, 2nd volume, 1st part, p. 146ff. Full text
- ↑ a b c d e f Jean D'Ans, Ellen Lax: Paperback for chemists and physicists: Volume 3 . Springer, 2007, ISBN 978-3-540-60035-0 ( page 532 in the Google book search).
- ↑ David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. CRC Press, 2009, ISBN 978-1-4200-9084-0 .
- ↑ This substance has either not yet been classified with regard to its hazardousness or a reliable and citable source has not yet been found.
- ^ AF Holleman , E. Wiberg , N. Wiberg : Textbook of Inorganic Chemistry . 101st edition. Walter de Gruyter, Berlin 1995, ISBN 3-11-012641-9 , p. 1150.
- ↑ M. Zafar, A. Munshi: Handbook of solid state batteries & capacitors . 1995, ISBN 978-981-02-1794-5 ( page 430 in the Google book search).
- ^ Georg Wittig, Günther Harborth: About the behavior of non-aromatic halides and ethers towards phenyllithium . In: Reports of the German Chemical Society . 77, No. 5, July 1944, pp. 306-314. doi : 10.1002 / cber.19440770505 .
- ↑ Robert Juza , Volker Wehle: Crystal structure of lithium carbide. In: The natural sciences. 52, 1965, pp. 537-537, doi : 10.1007 / BF00645818 .