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| Names | |||
|---|---|---|---|
| Preferred IUPAC name Trichloro(fluoro)methane | |||
| Other names Trichlorofluoromethane Fluorotrichloromethane Fluorochloroform Freon 11 CFC 11 R 11 Arcton 9 Freon 11A Freon 11B Freon HE Freon MF | |||
| Identifiers | |||
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3D model (JSmol) | |||
| ChEBI | |||
| ChEMBL | |||
| ChemSpider |
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| ECHA InfoCard | 100.000.812 | ||
| EC Number |
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| RTECS number |
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| UNII | |||
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| Properties | |||
| CCl3F | |||
| Molar mass | 137.36 g·mol−1 | ||
| Appearance | Colorless liquid/gas | ||
| Odor | nearly odorless[1] | ||
| Density | 1.494 g/cm3 | ||
| Melting point | −110.48 °C (−166.86 °F; 162.67 K) | ||
| Boiling point | 23.77 °C (74.79 °F; 296.92 K) | ||
| Critical point (T,P) | 198 °C (471 K), 4.410 MPa (44.1 bar) | ||
| 1.1 g/L (at 20 °C) | |||
| logP | 2.53 | ||
| Vapor pressure | 89 kPa at 20 °C 131 kPa at 30 °C | ||
| Thermal conductivity | 0.0079 W m−1 K−1 (gas at 300 K, ignoring pressure dependence)[2][verification needed] | ||
Refractive index (nD) | 1.3821 | ||
| 0.450 D | |||
| Hazards | |||
| GHS labelling:[4] | |||
 | |||
| Warning | |||
| H420 | |||
| P502 | |||
| Flash point | Non-flammable | ||
| Lethal dose or concentration (LD, LC): | |||
LCLo (lowest published) | 26,200 ppm (rat, 4 hr) 100,000 ppm (rat, 20 min) 100,000 ppm (rat, 2 hr)[3] | ||
| NIOSH (US health exposure limits): | |||
PEL (Permissible) | TWA 1000 ppm (5600 mg/m3)[1] | ||
REL (Recommended) | C 1000 ppm (5600 mg/m3)[1] | ||
IDLH (Immediate danger) | 2000 ppm[1] | ||
| Safety data sheet (SDS) | ICSC 0047 | ||
| Supplementary data page | |||
| Trichlorofluoromethane (data page) | |||
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |||
Trichlorofluoromethane, also calledfreon-11,CFC-11, orR-11, is achlorofluorocarbon (CFC). It is a colorless, faintly ethereal, and sweetish-smelling liquid that boils around room temperature.[5] CFC-11 is a Class 1ozone-depleting substance which damages Earth's protectivestratospheric ozone layer.[6] R-11 is not flammable at ambient temperature and pressure but it can become very combustible if heated and ignited by a strong ignition source.
Trichlorofluoromethane was first widely used as arefrigerant. Because of its high boiling point compared to most refrigerants, it can be used in systems with a low operating pressure, making the mechanical design of such systems less demanding than that of higher-pressure refrigerantsR-12 orR-22.
Trichlorofluoromethane is used as a reference compound forfluorine-19 NMR studies.
Trichlorofluoromethane was formerly used in thedrinking bird novelty, largely because it has a boiling point of 23.77 °C (74.79 °F). The replacement,dichloromethane, boiling point 39.6 °C (103.3 °F), requires a higher ambient temperature to work.
Prior to the knowledge of the ozone depletion potential of chlorine in refrigerants and other possible harmful effects on the environment, trichlorofluoromethane was sometimes used as a cleaning/rinsing agent for low-pressure systems.[7]
Trichlorofluoromethane can be obtained by reactingcarbon tetrachloride withhydrogen fluoride at 435 °C and 70 atm, producing a mixture of trichlorofluoromethane,tetrafluoromethane anddichlorodifluoromethane in a ratio of 77:18:5. The reaction can also be carried out in the presence ofantimony(III) chloride orantimony(V) chloride:[8]
Trichlorofluoromethane is also formed as one of the byproducts whengraphite reacts with chlorine and hydrogen fluoride at 500 °C.[8]
Sodium hexafluorosilicate under pressure at 270 °C,titanium(IV) fluoride,chlorine trifluoride,cobalt(III) fluoride,iodine pentafluoride, andbromine trifluoride are also suitable fluorinating agents for carbon tetrachloride.[8][9]
Trichlorofluoromethane was included in the production moratorium in theMontreal Protocol of 1987. It is assigned anozone depletion potential of 1.0, and U.S. production was ended on January 1, 1996.[6]
In 2018, the atmospheric concentration of CFC-11 was noted by researchers to be declining more slowly than expected,[10][11] and it subsequently emerged that it remains in widespread use as ablowing agent forpolyurethane foam insulation in the construction industry ofChina.[12] In 2021, researchers announced that emissions declined by 20,000 U.S. tons from 2018 to 2019, which mostly reversed the previous spike in emissions.[13] In 2022, theEuropean Commission announced an updated regulation that mandates the recovery and prevention of emissions of CFC-11 blowing agents from foam insulation in demolition waste, which is still emitted at significant scale.[14]
R11, like mostchlorofluorocarbons, formsphosgene gas when exposed to a naked flame.[15]
Because trichlorofluoromethane is one of the easiest to detectchlorofluorocarbons produced by anthropogenic activity, it has been used in attempting to detect industrial pollution in the atmospheres of earth-like exoplanets.[16]
Decline of CFC-11 has slowed in recent years, pointing to a renewed source
