Difluoromethane

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Difluoromethane
IUPAC name Difluoromethane
Other names Methylene fluoride, Methylene difluoride, Carbon fluoride hydride, HFC 32, R 32, FC 32, Freon 32, UN 3252
Identifiers
CAS number [75-10-5]
PubChem 6345
EINECS number 200-839-4
RTECS number PA8537500
SMILES C(F)F
InChI 1/CH2F2/c2-1-3/h1H2
Properties
Molecular formula 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
MSDS MSDS at Oxford University
EU classification Extremely flammable (F+)
NFPA 704
4
1
1
 
R-phrases R12
S-phrases S9, S16, S23
Autoignition
temperature		 648 °C
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)
Infobox disclaimer and references

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 It is based on methane, except that two of the four hydrogen atoms have been replaced by fluorine atoms.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.

Contents

[edit] 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

[edit] 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].

[edit] See also

[edit] External links

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