Difluoromethane 1426766 223258176 2008-07-03T08:11:56Z VolkovBot 3035831 robot Adding: [[de:Difluormethan]] {{Chembox new | ImageFileL1 = Difluoromethane-2D.svg | ImageSizeL1 = | ImageFileR1 = Difluoromethane-3D-vdW.png | ImageSizeR1 = | IUPACName = Difluoromethane | OtherNames = Methylene fluoride, Methylene difluoride, Carbon fluoride hydride, HFC 32, R 32, FC 32, Freon 32, UN 3252 | Section1 = {{Chembox Identifiers | CASNo = 75-10-5 | EINECS = 200-839-4 | PubChem = 6345 | SMILES = C(F)F | InChI = 1/CH2F2/c2-1-3/h1H2 | RTECS = PA8537500 }} | Section2 = {{Chembox Properties | Formula = CH<sub>2</sub>F<sub>2</sub> | MolarMass = 52.02 g/mol | Appearance = Colorless gas | Density = 2.72 kg/m<sup>3</sup> at 15&nbsp;°C (59&nbsp;°F)<br/> 2.163 kg/m<sup>3</sup> at 21.1&nbsp;°C (70&nbsp;°F) | MeltingPt = −136 °C | BoilingPt = −51.6 °C | Solubility = | VaporPressure = 1518.92 kPa at 21.1&nbsp;°C (70&nbsp;°F) }} | Section3 = {{Chembox Hazards | EUClass = Extremely flammable ('''F+''') | ExternalMSDS = [http://ptcl.chem.ox.ac.uk/MSDS/DI/difluoromethane.html MSDS at Oxford University] | MainHazards = | FlashPt = | Autoignition = 648 °C | RPhrases = {{R12}} | SPhrases = {{S9}}, {{S16}}, {{S23}} | NFPA-H = 1 | NFPA-F = 4 | NFPA-R = 1 | NFPA-O = }} }} '''Difluoromethane''', also called '''HFC-32''' or '''R-32''', is an [[organic compound]] of the [[Haloalkane|dihalogenoalkane]] variety. It is based on [[methane]], except that two of the four [[hydrogen]] atoms have been replaced by [[fluorine]] atoms. Hence the formula is CH<sub>2</sub>F<sub>2</sub> instead of CH<sub>4</sub> for normal methane. == Physical properties == {| class="wikitable" ! Property ! Value |- | [[Critical pressure]] (p<sub>c</sub>) | 5.83 MPa |- | [[Critical temperature]] (T<sub>c</sub>) | 78.45 °C (351 K) |- | [[Compressibility factor]] (Z) | 0.9863 |- | [[Specific heat capacity|Heat capacity]] at constant pressure (C<sub>p</sub>) at 21 °C (70 °F) | 0.043 kJ·mol<sup>−1</sup>·K<sup>−1</sup> |- | [[Specific heat capacity|Heat capacity]] at constant volume (C<sub>V</sub>) at 21 °C (70 °F) | 0.034 kJ·mol<sup>−1</sup>·K<sup>−1</sup> |- | [[Heat capacity ratio]] (κ) | 1.253 |- |} == Uses == Difluoromethane is a [[refrigerant]] that has zero [[ozone depletion potential]]. Difluoromethane in an [[azeotrope|azeotropic]] mixture with [[pentafluoroethane]] is known as [[R-410A]], a common replacement for various [[chlorofluorocarbons]] (aka ''[[Freon]]'') in new [[refrigerant]] systems. Although it has zero ozone depletion potential, it has high [[global warming potential]], 550 times that of carbon dioxide, based on a 100-year time frame [http://www.maine.gov/dep/air/emissions/ghg-equiv.htm]. == See also == * [[Haloalkane]] * [[Halomethane]] * [[Dichloromethane]] * [[Dibromomethane]] * [[Diiodomethane]] * [[Fluoromethane]] * [[Fluoroform]] (Trifluoromethane) * [[Tetrafluoromethane]] == External links == * [http://www.fire.nist.gov/bfrlpubs/fire99/art047.html Flammability Measurements of Difluoromethane in Air at 100° C] * [http://encyclopedia.airliquide.com/encyclopedia.asp?GasID=108 Difluoromethane at Gas Encyclopaedia] * [http://www.nist.gov/kinetics/spectra/ir_spectra/CH2F2%20(HFC-32).pdf IR absorption spectra] [[Category:Organofluorides]] [[Category:Halomethanes]] [[Category:Refrigerants]] [[de:Difluormethan]] [[ja:ジフルオロメタン]] [[zh:二氟甲烷]]