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Dichlorodifluoromethane

January 01, 1970

Dichlorodifluoromethane (R-12) is a colorless gas usually sold under the brand name Freon-12, and a chlorofluorocarbon halomethane (CFC) used as a refrigerant and aerosol spray propellant. In compliance with the Montreal Protocol, its manufacture was banned in developed countries (non-article 5 countries) in 1996, and in developing countries (Article 5 countries) in 2010 out of concerns about its damaging effect on the ozone layer.[5] Its only allowed usage is as a fire retardant in submarines and aircraft. It is soluble in many organic solvents. R-12 cylinders are colored white.

Dichlorodifluoromethane
Names
Preferred IUPAC name
Dichlorodi(fluoro)methane
Other names
  • Dichlorodifluoromethane
  • Carbon dichloride difluoride
  • Dichloro-difluoro-methane
  • Difluorodichloromethane
  • Freon 12
  • R-12
  • CFC-12
  • P-12
  • Propellant 12
  • Halon 122
  • Arcton 6
  • Arcton 12
  • E940
  • Fluorocarbon 12
  • Genetron 12
  • Refrigerant 12
Identifiers
  • 75-71-8 Y
3D model (JSmol)
  • Interactive image
ChEMBL
  • ChEMBL2106634 N
ChemSpider
  • 6151 Y
ECHA InfoCard 100.000.813
EC Number
  • 200-893-9
E number E940 (glazing agents, ...)
KEGG
  • D03789 Y
  • 6391
RTECS number
  • PA8200000
UNII
  • OFM06SG1KO Y
UN number 1028
  • DTXSID6020436
  • InChI=1S/CCl2F2/c2-1(3,4)5 Y
    Key: PXBRQCKWGAHEHS-UHFFFAOYSA-N Y
  • InChI=1/CCl2F2/c2-1(3,4)5
    Key: PXBRQCKWGAHEHS-UHFFFAOYAX
  • ClC(Cl)(F)F
Properties
CCl2F2
Molar mass 120.91 g·mol−1
Appearance Colorless gas
Odor ether-like at very high concentrations
Density 1.486 g/cm3 (−29.8 °C (−21.6 °F))
Melting point −157.7 °C (−251.9 °F; 115.5 K)
Boiling point −29.8 °C (−21.6 °F; 243.3 K)
0.286 g/L at 20 °C (68 °F)
Solubility in alcohol, ether, benzene, acetic acid Soluble
log P 2.16
Vapor pressure 568 kPa (20 °C (68 °F))
0.0025 mol kg−1 bar−1
−52.2·10−6 cm3/mol
Thermal conductivity 0.0097 W/(m·K) (300 K)[1]
Structure
Tetrahedral
0.51 D[2]
Hazards
GHS labelling:
Warning
H280, H336, H420
P261, P271, P304+P340, P319, P403+P233, P405, P410+P403, P501, P502
NFPA 704 (fire diamond)
Health 0: Exposure under fire conditions would offer no hazard beyond that of ordinary combustible material. E.g. sodium chlorideFlammability 0: Will not burn. E.g. waterInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
0
0
0
Flash point Non-flammable[3]
Lethal dose or concentration (LD, LC):
760,000 ppm (mouse, 30 min)
800,000 ppm (rabbit, 30 min)
800,000 ppm (guinea pig, 30 min)
600,000 ppm (rat, 2 h)[4]
NIOSH (US health exposure limits):
PEL (Permissible)
 TWA 1000 ppm (4950 mg/m3)[3]
REL (Recommended)
 TWA 1000 ppm (4950 mg/m3)[3]
IDLH (Immediate danger)
 15000 ppm[3]
Supplementary data page
Dichlorodifluoromethane (data page)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N verify (what is YN ?)

Preparation edit

It can be prepared by reacting carbon tetrachloride with hydrogen fluoride in the presence of a catalytic amount of antimony pentachloride:

CCl4 + 2HF → CCl2F2 + 2HCl

This reaction can also produce trichlorofluoromethane (CCl3F), chlorotrifluoromethane (CClF3) and tetrafluoromethane (CF4).[6]

History edit

Charles Kettering, vice president of General Motors Research Corporation, was seeking a refrigerant replacement that would be colorless, odorless, tasteless, nontoxic, and nonflammable. He assembled a team that included Thomas Midgley, Jr., Albert Leon Henne, and Robert McNary. From 1930 to 1935, they developed dichlorodifluoromethane (CCl2F2 or R12), trichlorofluoromethane (CCl3F or R11), chlorodifluoromethane (CHClF2 or R22), trichlorotrifluoroethane (CCl2FCClF2 or R113), and dichlorotetrafluoroethane (CClF2CClF2 or R114), through Kinetic Chemicals which was a joint venture between DuPont and General Motors.[7]

Use as an aerosol edit

The use of chlorofluorocarbons as aerosols in medicine, such as USP-approved salbutamol, has been phased out by the U.S. Food and Drug Administration. A different propellant known as hydrofluoroalkane, or HFA, which was not known to harm the environment, was chosen to replace it.[8]

Retrofitting edit

R-12 was used in most refrigeration and vehicle air conditioning applications prior to 1994 before being replaced by 1,1,1,2-tetrafluoroethane (R-134a), which has an insignificant ozone depletion potential. Automobile manufacturers started using R-134a instead of R-12 in 1992–1994. When older units leak or require repair involving removal of the refrigerant, retrofitment to a refrigerant other than R-12 (most commonly R-134a which has a global warming potential 3,400 times that of carbon dioxide) is required in some jurisdictions. The United States does not require automobile owners to retrofit their systems; however, taxes on ozone-depleting chemicals coupled with the relative scarcity of the original refrigerants on the open market make retrofitting the only economical option. Retrofitment requires a system flush and a new filter/dryer or accumulator, and may also involve the installation of new seals and/or hoses made of materials compatible with the refrigerant being installed. Mineral oil used with R-12 is not compatible with R-134a. Some oils designed for conversion to R-134a are advertised as compatible with residual R-12 mineral oil. Another replacement for R-12 is the highly flammable, but truly drop-in HC-12a, whose flammability has led to injuries and deaths in a bus fire in 2006.[9][10]

Dangers edit

Aside from its environmental impacts, R12, like most chlorofluoroalkanes, forms phosgene gas when exposed to a naked flame.[11]

Properties edit

Table of thermal and physical properties of saturated liquid refrigerant 12:[12][13]

Temperature (°C) Density (kg/m^3) Specific heat (kJ/kg K) Kinematic viscosity (m^2/s) Conductivity (W/m K) Thermal diffusivity (m^2/s) Prandtl Number Bulk modulus (K^-1)
-50 1546.75 0.875 3.10E-07 0.067 5.01E-01 6.2 2.63E-03
-40 1518.71 0.8847 2.79E-07 0.069 5.14E-01 5.4 -
-30 1489.56 0.8956 2.53E-07 0.069 5.26E-01 4.8 -
-20 1460.57 0.9073 2.35E-07 0.071 5.39E-01 4.4 -
-10 1429.49 0.9203 2.21E-07 0.073 5.50E-01 4 -
0 1397.45 0.9345 2.14E-07 0.073 5.57E-01 3.8 -
10 1364.3 0.9496 2.03E-07 0.073 5.60E-01 3.6 -
20 1330.18 0.9659 1.98E-07 0.073 5.60E-01 3.5 -
30 1295.1 0.9835 1.94E-07 0.071 5.60E-01 3.5 -
40 1257.13 1.0019 1.91E-07 0.069 5.55E-01 3.5 -
50 1215.96 1.0216 1.90E-07 0.067 5.45E-01 3.5 -

Gallery edit

  •  
    CFC-12 measured by the Advanced Global Atmospheric Gases Experiment (AGAGE) in the lower atmosphere (troposphere) at stations around the world. Abundances are given as pollution free monthly mean mole fractions in parts-per-trillion.
  •  
    Hemispheric and global mean CFC-12 concentrations (NOAA/ESRL)
  •  
    Time-series of atmospheric concentrations of CFC-12 (Walker et al., 2000)
  •  
    1990s sea surface CFC-12 concentration
  •  
    1990s CFC-12 oceanic vertical inventory
  •  
    CFC-12, CFC-11, H-1211 and SF6 vertical profiles

References edit

  1. ^ Touloukian, Y. S., Liley, P. E., and Saxena, S. C. Thermophysical properties of matter – the TPRC data series. Volume 3. Thermal conductivity – nonmetallic liquids and gases. Data book. 1970.
  2. ^ Khristenko, Sergei V.; Maslov, Alexander I. and Viatcheslav P. Shevelko; Molecules and Their Spectroscopic Properties, p. 74 ISBN 3642719481.
  3. ^ a b c d NIOSH Pocket Guide to Chemical Hazards. "#0192". National Institute for Occupational Safety and Health (NIOSH).
  4. ^ "Dichlorodifluoromethane". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
  5. ^ "1:Update on Ozone-Depleting Substances (ODSs) and Other Gases of Interest to the Montreal Protocol". Scientific assessment of ozone depletion: 2018 (PDF) (Global Ozone Research and Monitoring Project–Report No. 58 ed.). Geneva, Switzerland: World Meteorological Organization. 2018. p. 1.10. ISBN 978-1-7329317-1-8. Retrieved 22 November 2020.
  6. ^ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. p. 304. ISBN 978-0-08-037941-8.
  7. ^ Plunkett, Roy J. (1986). High Performance Polymers: Their Origin and Development. Elsevier Science Publishing Co., Inc. pp. 261–262. ISBN 978-94-011-7073-4.
  8. ^ . 16 February 2007. Archived from the original on 16 February 2007. Retrieved 26 April 2022.
  9. ^ "Se cumplen 13 años de la Tragedia de la Cresta". Ensegundos.com.pa. 23 October 2019.
  10. ^ "Victims of the La Cresta tragedy were remembered". M.metrolibra.com. Retrieved 26 April 2022.
  11. ^ "False Alarms: The Legacy of Phosgene Gas". HVAC School. 4 January 2021. Retrieved 9 May 2022.
  12. ^ Holman, Jack P. (2002). Heat Transfer (9th ed.). New York, NY: McGraw-Hill Companies, Inc. pp. 600–606. ISBN 9780072406559.
  13. ^ Incropera 1 Dewitt 2 Bergman 3 Lavigne 4, Frank P. 1 David P. 2 Theodore L. 3 Adrienne S. 4 (2007). Fundamentals of Heat and Mass Transfer (6th ed.). Hoboken, NJ: John Wiley and Sons, Inc. pp. 941–950. ISBN 9780471457282.{{cite book}}: CS1 maint: numeric names: authors list (link)

External links edit

  • NOAA/ESRL CFC-12 global measurements
  • International Chemical Safety Card 0048
  • Overview of Freon-12 and some of its environmental problems
  • Thermochemistry data at chemnet.ru
  • CDC - NIOSH Pocket Guide to Chemical Hazards

January 01, 1970
dichlorodifluoromethane, colorless, usually, sold, under, brand, name, freon, chlorofluorocarbon, halomethane, used, refrigerant, aerosol, spray, propellant, compliance, with, montreal, protocol, manufacture, banned, developed, countries, article, countries, 1. Dichlorodifluoromethane R 12 is a colorless gas usually sold under the brand name Freon 12 and a chlorofluorocarbon halomethane CFC used as a refrigerant and aerosol spray propellant In compliance with the Montreal Protocol its manufacture was banned in developed countries non article 5 countries in 1996 and in developing countries Article 5 countries in 2010 out of concerns about its damaging effect on the ozone layer 5 Its only allowed usage is as a fire retardant in submarines and aircraft It is soluble in many organic solvents R 12 cylinders are colored white Dichlorodifluoromethane Names Preferred IUPAC name Dichlorodi fluoro methane Other names DichlorodifluoromethaneCarbon dichloride difluorideDichloro difluoro methaneDifluorodichloromethaneFreon 12R 12CFC 12P 12Propellant 12Halon 122Arcton 6Arcton 12E940Fluorocarbon 12Genetron 12Refrigerant 12 Identifiers CAS Number 75 71 8 Y 3D model JSmol Interactive image ChEMBL ChEMBL2106634 N ChemSpider 6151 Y ECHA InfoCard 100 000 813 EC Number 200 893 9 E number E940 glazing agents KEGG D03789 Y PubChem CID 6391 RTECS number PA8200000 UNII OFM06SG1KO Y UN number 1028 CompTox Dashboard EPA DTXSID6020436 InChI InChI 1S CCl2F2 c2 1 3 4 5 YKey PXBRQCKWGAHEHS UHFFFAOYSA N YInChI 1 CCl2F2 c2 1 3 4 5Key PXBRQCKWGAHEHS UHFFFAOYAX SMILES ClC Cl F F Properties Chemical formula C Cl 2F 2 Molar mass 120 91 g mol 1 Appearance Colorless gas Odor ether like at very high concentrations Density 1 486 g cm3 29 8 C 21 6 F Melting point 157 7 C 251 9 F 115 5 K Boiling point 29 8 C 21 6 F 243 3 K Solubility in water 0 286 g L at 20 C 68 F Solubility in alcohol ether benzene acetic acid Soluble log P 2 16 Vapor pressure 568 kPa 20 C 68 F Henry s lawconstant kH 0 0025 mol kg 1 bar 1 Magnetic susceptibility x 52 2 10 6 cm3 mol Thermal conductivity 0 0097 W m K 300 K 1 Structure Molecular shape Tetrahedral Dipole moment 0 51 D 2 Hazards GHS labelling Pictograms Signal word Warning Hazard statements H280 H336 H420 Precautionary statements P261 P271 P304 P340 P319 P403 P233 P405 P410 P403 P501 P502 NFPA 704 fire diamond 000 Flash point Non flammable 3 Lethal dose or concentration LD LC LC50 median concentration 760 000 ppm mouse 30 min 800 000 ppm rabbit 30 min 800 000 ppm guinea pig 30 min 600 000 ppm rat 2 h 4 NIOSH US health exposure limits PEL Permissible TWA 1000 ppm 4950 mg m3 3 REL Recommended TWA 1000 ppm 4950 mg m3 3 IDLH Immediate danger 15000 ppm 3 Supplementary data page Dichlorodifluoromethane data page Except where otherwise noted data are given for materials in their standard state at 25 C 77 F 100 kPa N verify what is Y N Infobox references Contents 1 Preparation 2 History 3 Use as an aerosol 4 Retrofitting 5 Dangers 6 Properties 7 Gallery 8 References 9 External linksPreparation editIt can be prepared by reacting carbon tetrachloride with hydrogen fluoride in the presence of a catalytic amount of antimony pentachloride CCl4 2HF CCl2F2 2HCl This reaction can also produce trichlorofluoromethane CCl3F chlorotrifluoromethane CClF3 and tetrafluoromethane CF4 6 History editCharles Kettering vice president of General Motors Research Corporation was seeking a refrigerant replacement that would be colorless odorless tasteless nontoxic and nonflammable He assembled a team that included Thomas Midgley Jr Albert Leon Henne and Robert McNary From 1930 to 1935 they developed dichlorodifluoromethane CCl2F2 or R12 trichlorofluoromethane CCl3F or R11 chlorodifluoromethane CHClF2 or R22 trichlorotrifluoroethane CCl2FCClF2 or R113 and dichlorotetrafluoroethane CClF2CClF2 or R114 through Kinetic Chemicals which was a joint venture between DuPont and General Motors 7 Use as an aerosol editThe use of chlorofluorocarbons as aerosols in medicine such as USP approved salbutamol has been phased out by the U S Food and Drug Administration A different propellant known as hydrofluoroalkane or HFA which was not known to harm the environment was chosen to replace it 8 Retrofitting editR 12 was used in most refrigeration and vehicle air conditioning applications prior to 1994 before being replaced by 1 1 1 2 tetrafluoroethane R 134a which has an insignificant ozone depletion potential Automobile manufacturers started using R 134a instead of R 12 in 1992 1994 When older units leak or require repair involving removal of the refrigerant retrofitment to a refrigerant other than R 12 most commonly R 134a which has a global warming potential 3 400 times that of carbon dioxide is required in some jurisdictions The United States does not require automobile owners to retrofit their systems however taxes on ozone depleting chemicals coupled with the relative scarcity of the original refrigerants on the open market make retrofitting the only economical option Retrofitment requires a system flush and a new filter dryer or accumulator and may also involve the installation of new seals and or hoses made of materials compatible with the refrigerant being installed Mineral oil used with R 12 is not compatible with R 134a Some oils designed for conversion to R 134a are advertised as compatible with residual R 12 mineral oil Another replacement for R 12 is the highly flammable but truly drop in HC 12a whose flammability has led to injuries and deaths in a bus fire in 2006 9 10 Dangers editAside from its environmental impacts R12 like most chlorofluoroalkanes forms phosgene gas when exposed to a naked flame 11 Properties editTable of thermal and physical properties of saturated liquid refrigerant 12 12 13 Temperature C Density kg m 3 Specific heat kJ kg K Kinematic viscosity m 2 s Conductivity W m K Thermal diffusivity m 2 s Prandtl Number Bulk modulus K 1 50 1546 75 0 875 3 10E 07 0 067 5 01E 01 6 2 2 63E 03 40 1518 71 0 8847 2 79E 07 0 069 5 14E 01 5 4 30 1489 56 0 8956 2 53E 07 0 069 5 26E 01 4 8 20 1460 57 0 9073 2 35E 07 0 071 5 39E 01 4 4 10 1429 49 0 9203 2 21E 07 0 073 5 50E 01 4 0 1397 45 0 9345 2 14E 07 0 073 5 57E 01 3 8 10 1364 3 0 9496 2 03E 07 0 073 5 60E 01 3 6 20 1330 18 0 9659 1 98E 07 0 073 5 60E 01 3 5 30 1295 1 0 9835 1 94E 07 0 071 5 60E 01 3 5 40 1257 13 1 0019 1 91E 07 0 069 5 55E 01 3 5 50 1215 96 1 0216 1 90E 07 0 067 5 45E 01 3 5 Gallery edit nbsp CFC 12 measured by the Advanced Global Atmospheric Gases Experiment AGAGE in the lower atmosphere troposphere at stations around the world Abundances are given as pollution free monthly mean mole fractions in parts per trillion nbsp Hemispheric and global mean CFC 12 concentrations NOAA ESRL nbsp Time series of atmospheric concentrations of CFC 12 Walker et al 2000 nbsp 1990s sea surface CFC 12 concentration nbsp 1990s CFC 12 oceanic vertical inventory nbsp CFC 12 CFC 11 H 1211 and SF6 vertical profilesReferences edit Touloukian Y S Liley P E and Saxena S C Thermophysical properties of matter the TPRC data series Volume 3 Thermal conductivity nonmetallic liquids and gases Data book 1970 Khristenko Sergei V Maslov Alexander I and Viatcheslav P Shevelko Molecules and Their Spectroscopic Properties p 74 ISBN 3642719481 a b c d NIOSH Pocket Guide to Chemical Hazards 0192 National Institute for Occupational Safety and Health NIOSH Dichlorodifluoromethane Immediately Dangerous to Life or Health Concentrations IDLH National Institute for Occupational Safety and Health NIOSH 1 Update on Ozone Depleting Substances ODSs and Other Gases of Interest to the Montreal Protocol Scientific assessment of ozone depletion 2018 PDF Global Ozone Research and Monitoring Project Report No 58 ed Geneva Switzerland World Meteorological Organization 2018 p 1 10 ISBN 978 1 7329317 1 8 Retrieved 22 November 2020 Greenwood Norman N Earnshaw Alan 1997 Chemistry of the Elements 2nd ed Butterworth Heinemann p 304 ISBN 978 0 08 037941 8 Plunkett Roy J 1986 High Performance Polymers Their Origin and Development Elsevier Science Publishing Co Inc pp 261 262 ISBN 978 94 011 7073 4 Asthma inhaler replacements coming to Pa Pittsburgh Tribune Review 16 February 2007 Archived from the original on 16 February 2007 Retrieved 26 April 2022 Se cumplen 13 anos de la Tragedia de la Cresta Ensegundos com pa 23 October 2019 Victims of the La Cresta tragedy were remembered M metrolibra com Retrieved 26 April 2022 False Alarms The Legacy of Phosgene Gas HVAC School 4 January 2021 Retrieved 9 May 2022 Holman Jack P 2002 Heat Transfer 9th ed New York NY McGraw Hill Companies Inc pp 600 606 ISBN 9780072406559 Incropera 1 Dewitt 2 Bergman 3 Lavigne 4 Frank P 1 David P 2 Theodore L 3 Adrienne S 4 2007 Fundamentals of Heat and Mass Transfer 6th ed Hoboken NJ John Wiley and Sons Inc pp 941 950 ISBN 9780471457282 a href Template Cite book html title Template Cite book cite book a CS1 maint numeric names authors list link External links editNOAA ESRL CFC 12 global measurements International Chemical Safety Card 0048 Overview of Freon 12 and some of its environmental problems MSDS at Oxford University Thermochemistry data at chemnet ru IR absorption spectra CDC NIOSH Pocket Guide to Chemical Hazards Retrieved from https en wikipedia org w index php title Dichlorodifluoromethane amp oldid 1214552381, wikipedia, wiki, book, books, library,

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