Hexafluoroethane
Structural formula | ||||||||||||||||
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General | ||||||||||||||||
Surname | Hexafluoroethane | |||||||||||||||
other names |
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Molecular formula | C 2 F 6 | |||||||||||||||
Brief description |
colorless and odorless gas |
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properties | ||||||||||||||||
Molar mass | 138.01 g mol −1 | |||||||||||||||
Physical state |
gaseous |
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density |
6.25 kg m −3 (under normal conditions ) |
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Melting point |
−101 ° C |
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boiling point |
−78.2 ° C |
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solubility |
slightly soluble in water |
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safety instructions | ||||||||||||||||
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Global warming potential |
12340 (based on 100 years) |
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Thermodynamic properties | ||||||||||||||||
ΔH f 0 |
−1344.2 kJ / mol |
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As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . |
Hexafluoroethane is a chemical compound from the group of fluorocarbons and is a perfluorocarbon as an aliphatic saturated fluorocarbon .
Presentation and extraction
One synthesis variant is the reaction of trifluoroacetic acid with xenon difluoride . Here, the unstable esters (CF 3 COO) 2 Xe and (CF 3 COO) XeF are first formed, the decomposition or decarboxylation of which leads to trifluoromethyl radicals and then to hexafluoroethane.
properties
Hexafluoroethane is a compressed gas in pressurized gas cylinders . Under 19.7 ° C under pressure it is a liquefied gas. When the liquid flows out or when large amounts of gas escape, cold mists form and spread across the floor. The compound decomposes above 800 ° C, producing hydrogen fluoride , carbon monoxide and carbon dioxide under air . The critical point is 19.89 ° C, 30.39 bar and 0.601 kg · l −1 ; the triple point at −100.10 ° C and 0.26490 bar.
Hexafluoroethane has a global warming potential of 12340 and an ozone depletion potential of 0.
use
Hexafluoroethane is used in the semiconductor industry as an etching gas and in plasma etching , as well as for cleaning CVD chambers . It also serves as a propellant gas , gaseous insulating material (in foamed materials) and as a refrigerant . Large amounts of hexafluoroethane are released during aluminum production.
safety instructions
Hexafluoroethane is heavier than air and suffocating in high concentrations.
Individual evidence
- ↑ a b c d e f g h Entry on hexafluoroethane in the GESTIS substance database of the IFA , accessed on February 22, 2017(JavaScript required) .
- ↑ G. Myhre, D. Shindell et al .: Climate Change 2013: The Physical Science Basis . Working Group I contribution to the IPCC Fifth Assessment Report. Ed .: Intergovernmental Panel on Climate Change . 2013, Chapter 8: Anthropogenic and Natural Radiative Forcing, pp. 24-39; Table 8.SM.16 ( PDF ).
- ↑ David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Standard Thermodynamic Properties of Chemical Substances, pp. 5-21.
- ↑ e-EROS Encyclopedia of Reagents for Organic Synthesis , 1999–2013, John Wiley and Sons, Inc., entry for Xenon (II) fluoride, accessed January 20, 2018 .
- ↑ Helmut Schan: Handbook of the purest gases. Springer, 2005, ISBN 978-3-540-23215-5 , p. 307.
- ↑ hexafluoroethane (airliquide)
- ↑ R116 (Linde gas)