Carbon tetrafluoride
 Carbon tetrafluoride | |
|---|---|
type of chemical entity (en)  | |
| Bayanai | |
| Ƙaramin ɓangare na |
halon (en) , perfluoroalkane (en) , tetrahalomethane (en) da per- and polyfluoroalkyl substances (en) |
| Sinadaran dabara | CF₄ |
| Canonical SMILES (en) | C(F)(F)(F)F |
| Safety classification and labelling (en) |
NFPA 704: Standard System for the Identification of the Hazards of Materials for Emergency Response (en) |
Tetrafluoromethane, wanda kuma aka sani da carbon tetrafluoride ko R-14, shine mafi sauƙi perfluorocarbon ( C F 4 ). Kamar yadda sunan IUPAC ya nuna, tetrafluoromethane shine takwaransa mai gurbataccen ruwa zuwa methane na hydrocarbon. Hakanan ana iya rarraba shi azaman haloalkane ko halomethane . Tetrafluoromethane mai sanyi ne mai amfani amma kuma iskar gas mai ƙarfi. Yana da ƙarfin haɗin gwiwa sosai saboda yanayin haɗin carbon-fluorine .
jingina
[gyara sashe | gyara masomin]Saboda mahara carbon-fluorine bond, da kuma high electronegativity na fluorine, da carbon a tetrafluoromethane yana da wani gagarumin m m cajin wanda ya karfafa da kuma rage hudu carbon-fluorine bond ta samar da ƙarin ionic hali. Abubuwan haɗin carbon-fluorine sune mafi ƙarfi guda ɗaya a cikin sinadarai na halitta . [1] Bugu da ƙari, suna ƙarfafa yayin da ake ƙara ƙarin abubuwan haɗin carbon-fluorine zuwa carbon atom iri ɗaya. A cikin mahaɗin organofluorine guda ɗaya-carbon wanda ke wakiltar kwayoyin fluoromethane, difluoromethane, trifluoromethane, da tetrafluoromethane, haɗin carbon-fluorine sun fi karfi a cikin tetrafluoromethane. [2] Wannan tasirin ya faru ne saboda haɓakar abubuwan jan hankali na coulombic tsakanin atom ɗin fluorine da carbon saboda carbon yana da ingantaccen caji na 0.76. [2]
Shiri
[gyara sashe | gyara masomin]Tetrafluoromethane shine samfurin lokacin da kowane fili na carbon, gami da carbon kanta, ya ƙone a cikin yanayin fluorine. Tare da hydrocarbons, hydrogen fluoride shine kwafi. An fara ba da rahoto a cikin 1926. Hakanan za'a iya shirya shi ta hanyar fluorination na carbon dioxide, carbon monoxide ko phosgene tare da tetrafluoride sulfur . A kasuwanci ana kera shi ta hanyar amsawar hydrogen fluoride tare da dichlorodifluoromethane ko chlorotrifluoromethane ; Ana kuma samar da shi a lokacin electrolysis na karfe fluorides MF, MF 2 ta amfani da carbon electrode.
Ko da yake ana iya yin shi daga ɗimbin abubuwan precursors da fluorine, furotin na asali yana da tsada kuma yana da wuyar iyawa. A sakamakon haka, CF An shirya CF akan sikelin masana'antu ta amfani da hydrogen fluoride :
- CCl 2 F 2 + 2 HF → CF 4 + 2 HCl
Laboratory kira
[gyara sashe | gyara masomin]Ana iya shirya Tetrafluoromethane da silicon tetrafluoride a cikin dakin gwaje-gwaje ta hanyar amsawar silicon carbide tare da fluorine.
- SiC + 4 F 2 → CF 4 + SiF 4
Martani
[gyara sashe | gyara masomin]Tetrafluoromethane, kamar sauran fluorocarbons, yana da ƙarfi sosai saboda ƙarfin haɗin gwiwar carbon-fluorine. Abubuwan da ke cikin tetrafluoromethane suna da ƙarfin haɗin gwiwa na 515 kJ⋅mol -1 . A sakamakon haka, shi ne inert zuwa acid da hydroxides. Duk da haka, yana mayar da martani tare da karafa na alkali . Rushewar thermal ko konewar CF 4 yana samar da iskar gas mai guba ( carbonyl fluoride da carbon monoxide ) kuma a gaban ruwa kuma zai samar da hydrogen fluoride .
Yana da ɗan narkewa sosai cikin ruwa (kimanin 20 mg⋅L -1 ), amma sosai mai narkewa a cikin kwayoyin kaushi. Lokacin da ruwa ya cika, yana da gaba ɗaya miscible a cikin kwayoyin kaushi.
Amfani
[gyara sashe | gyara masomin]Tetrafluoromethane wani lokaci ana amfani dashi azaman mai sanyi mai ƙarancin zafin jiki (R-14). Ana amfani da shi a cikin microfabrication na lantarki kadai ko a hade tare da oxygen a matsayin wani abu na plasma don silicon, silicon dioxide, da silicon nitride . Har ila yau, yana da amfani a cikin injin gano neutron. [3]
Tasirin muhalli
[gyara sashe | gyara masomin]
Tetrafluoromethane shine iskar gas mai ƙarfi wanda ke ba da gudummawa ga tasirin greenhouse . Yana da karko sosai, yana da tsawon rayuwa na yanayi na shekaru 50,000, kuma yana da yuwuwar dumamar yanayi sau 6,500 fiye da na CO 2 . [4]
Tetrafluoromethane shine mafi yawan perfluorocarbon a cikin yanayi, inda aka sanya shi a matsayin PFC-14. Matsayinta na yanayi yana girma: [5] ƙaddamarwar masana'antu na farko da aka samar ta hanyar iskar oxygen oxidation na fluorite da amsawa tare da kwayoyin halitta bai wuce sassa 40 a kowace tiriliyan ba. [6] [lower-alpha 1] Tun daga shekarar 2019, iskar gas da mutum ya yi CFC-11 da CFC-12 suna ci gaba da ba da gudummawar daɗaɗɗa mai ƙarfi fiye da PFC-14. [7]
Ko da yake tsarin yana kama da chlorofluorocarbons (CFCs), tetrafluoromethane ba ya rage ledar sararin samaniya [8] saboda haɗin carbon-fluorine ya fi wannan ƙarfi tsakanin carbon da chlorine. [9]
Babban watsin masana'antu na tetrafluoromethane ban da hexafluoroethane ana samar da su yayin samar da aluminium ta amfani da tsarin Hall-Héroult . Hakanan ana samar da CF 4 azaman samfur na rushewar hadaddun mahadi kamar halocarbons . [10]
Hadarin lafiya
[gyara sashe | gyara masomin]Saboda yawansa, tetrafluoromethane na iya kawar da iska, yana haifar da haɗarin asphyxiation a wuraren da ba su da isasshen iska. In ba haka ba, yawanci ba shi da lahani saboda kwanciyar hankali.
Manazarta
[gyara sashe | gyara masomin]- ↑ O'Hagan D (February 2008). "Understanding organofluorine chemistry and in cations. An introduction to the C–F bond". Chemical Society Reviews. 37 (2): 308–19. doi:10.1039/b711844a. PMID 18197347.
- 1 2 Lemal, D.M. (2004). "Perspective on Fluorocarbon Chemistry". J. Org. Chem. 69 (1): 1–11. doi:10.1021/jo0302556. PMID 14703372.
- ↑ Moon, Myung-Kook; Nam, Uk-Won; Lee, Chang-Hee; Em, V.T.; Choi, Young-Hyun; Cheon, Jong-Kyu; Kong, Kyung-Nam (2005). "Low efficiency 2-dimensional position-sensitive neutron detector for beam profile measurement". Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 538 (1–3): 592–596. Bibcode:2005NIMPA.538..592M. doi:10.1016/j.nima.2004.09.020.
- ↑ Artaxo, Paulo; Berntsen, Terje; Betts, Richard; Fahey, David W.; Haywood, James; Lean, Judith; Lowe, David C.; Myhre, Gunnar; Nganga, John (February 2018). "Changes in Atmospheric Constituents and in Radiative Forcing" (PDF). Intergovernmental Panel on Climate Change. p. 212. Retrieved 17 March 2021.
- ↑ "Climate change indicators - Atmospheric concentration of greenhouse gases - Figure 4". United States Environmental Protection Agency. 27 June 2016. Retrieved 2020-09-26.
- ↑ Harnisch, Jochen; Eisenhauer, Anton (1998). "Natural CF4 and SF6 on Earth". Geophysical Research Letters. 25 (13): 2401–2404. Bibcode:1998GeoRL..25.2401H. doi:10.1029/98GL01779. S2CID 129805049.
- ↑ Butler J. and Montzka S. (2020). "The NOAA Annual Greenhouse Gas Index (AGGI)". NOAA Global Monitoring Laboratory/Earth System Research Laboratories.
- ↑ Cicerone, Ralph J. (1979-10-05). "Atmospheric Carbon Tetrafluoride: A Nearly Inert Gas" (PDF). Science (in Turanci). 206 (4414): 59–61. Bibcode:1979Sci...206...59C. doi:10.1126/science.206.4414.59. ISSN 0036-8075. PMID 17812452. S2CID 34911990.
- ↑ "Bond Energies". www2.chemistry.msu.edu. Retrieved 2023-01-15.
- ↑ Jubb, Aaron M.; McGillen, Max R.; Portmann, Robert W.; Daniel, John S.; Burkholder, James B. (2015). "An atmospheric photochemical source of the persistent greenhouse gas CF4". Geophysical Research Letters. 42 (21): 9505–9511. Bibcode:2015GeoRL..42.9505J. doi:10.1002/2015GL066193. ISSN 0094-8276.
- ↑ This figure is for all perfluorocarbons: no data for the preindustrial abundance of individual compounds of this class exist.
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