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Difluoromethane

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Difluoromethane
Names
IUPAC name
Difluoromethane
Other names
Methylene fluoride, Methylene difluoride, Carbon fluoride hydride, HFC 32, R 32, FC 32, Freon 32, UN 3252
Identifiers
3D model (JSmol)
ECHA InfoCard 100.000.764 Edit this at Wikidata
EC Number
  • 200-839-4
RTECS number
  • PA8537500
  • InChI=1/CH2F2/c2-1-3/h1H2
  • C(F)F
Properties
CH2F2
Molar mass 52.02 g/mol
Appearance Colorless gas
Density 2.72 kg/m3 at 15 °C (59 °F)

2.163 kg/m3 at 21.1 °C (70 °F)

Melting point −136 °C
Boiling point −51.6 °C
Vapor pressure 1518.92 kPa at 21.1 °C (70 °F)
Hazards
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 1: Exposure would cause irritation but only minor residual injury. E.g. turpentineFlammability 4: Will rapidly or completely vaporize at normal atmospheric pressure and temperature, or is readily dispersed in air and will burn readily. Flash point below 23 °C (73 °F). E.g. propaneInstability 1: Normally stable, but can become unstable at elevated temperatures and pressures. E.g. calciumSpecial hazards (white): no code
1
4
1
Supplementary data page
Difluoromethane (data page)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Difluoromethane, also called HFC-32 or R-32, is an organic compound of the 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 It is based on methane, except that two of the four hydrogen atoms have been replaced by fluorine atoms.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 CH2F2 instead of CH4 for normal methane.

Physical properties

Property Value
Critical pressure (pc) 5.83 MPa
Critical temperature (Tc) 78.45 °C (351 K)
Compressibility factor (Z) 0.9863
Heat capacity at constant pressure (Cp) at 21 °C (70 °F) 0.043 kJ·mol−1·K−1
Heat capacity at constant volume (CV) at 21 °C (70 °F) 0.034 kJ·mol−1·K−1
Heat capacity ratio (κ) 1.253

Uses

Difluoromethane is a refrigerant that has zero ozone depletion potential. Difluoromethane in an 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 [1].