Dichlorodifluoromethane Information & Dichlorodifluoromethane Links at HealthHaven.com

Dichlorodifluoromethane
IUPAC name	Dichlorodifluoromethane
Other names	Carbon dichloride difluoride, Dichloro-difluoro-methane, Difluorodichloromethane, Freon 12, R-12, CFC-12, P-12, Propellant 12, Halon 122, Arcton 6, Arcton 12, E940
Identifiers
CAS number	75-71-8
PubChem	6391
EC number	200-893-9
UN number	1028
KEGG	D03789
RTECS number	PA8200000
SMILES	C(F)(F)(Cl)Cl
InChI	1/CCl2F2/c2-1(3,4)5
Properties
Molecular formula	CCl2F2
Molar mass	120.91 g/mol
Appearance	Colorless gas with ether-like odor
Density	1.486 g/cm³ (−29.8 °C)
Melting point	−157.7 °C (115.5 K)
Boiling point	−29.8 °C (243.3 K)
Solubility in water	0.286 g/l at 20 °C
log P	2.16
Vapor pressure	568 kPa (20 °C)
kH	0.0025 mol kg-1 bar-1
Hazards
MSDS	ICSC 0048
EU Index	Not listed
Main hazards	Damaging to Earth's protective ozone
Flash point	Non-flammable
	(what is this?) (verify); Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
	Infobox references

Dichlorodifluoromethane (R-12), usually sold under the brand name Freon-12, is a chlorofluorocarbon halomethane (CFC), used as a refrigerant and aerosol spray propellant. Complying with the Montreal Protocol, its manufacture was banned in the United States along with many other countries in 1994 due to concerns about damage to the ozone layer.^[1] It is soluble in many organic solvents.

[edit] Physical properties

Property	Value
Density (ρ) at -29.8 °C (gas)	6.25 kg.m^-3
Density (ρ) at 15 °C (gas)	5.11 kg.m^-3
Triple point temperature (T_t)	-157 °C (116 K)
Triple point pressure (p_t)	10 Pa (0.00010 bar)
Critical temperature (T_c)	112 °C (385 K)
Critical pressure (p_c)	4.170 MPa (41.15 bar)
Critical density (ρ_c)	4.789 mol.l^-1
Latent heat of vaporization (l_v)	166.95 kJ.kg^-1
Specific heat capacity at constant pressure (C_p) at 30 °C	74 J.mol^-1.K^-1
Specific heat capacity at constant volume (C_v) at 30 °C	65 J.mol^-1.K^-1
Heat capacity ratio (κ) at 30 °C	1.138889
Vapor pressure (η) at -20 °C	151 kPa
Vapor pressure (η) at 0 °C	300 kPa
Vapor pressure (η) at 16 °C	500 kPa
Vapor pressure (η) at 20 °C	567 kPa
Vapor pressure (η) at 40 °C	960 kPa
Compressibility Factor (Z) at 21 °C	0.995
Viscosity (μ) at 0 °C	11.68 μPa.s (0.01168 cP)
Thermal conductivity (k) at 0 °C	9.46 mW.m^-1.K^-1
Ozone depletion potential (ODP)	1.0 (CCl₃F = 1)
Global warming potential (GWP)	8100 (CO₂ = 1)

[edit] Usage as an aerosol

The use of chlorofluorocarbons as an aerosol in medicine, for example: USP-approved Albuterol, has been phased out by the U.S. Food and Drug Administration. The use of a different propellant known as hydrofluoroalkane, or HFA, which does not harm the environment has been chosen as the replacement. [1]

[edit] Retrofitting

R-12 was primarily used in automobiles produced prior to 1994. For older vehicles, retrofits to R-134a (1,1,1,2-tetrafluoroethane) are generally recommended. Retrofits usually include a complete flushing of the air conditioning system to remove the oil. The oils used for R12 and R-134a are not generally compatible, although some oils designed for conversion to R-134a are advertised as compatible with residual R-12. Additionally a new compressor, expansion valve, and dryer may be needed. In some cases, all new rubber hoses are needed. It is worth noting that after changing the valves, hoses, and compressor, the only original components of the air conditioner remaining are the evaporator and condenser, neither of which have moving or delicate pieces. Replacement components are usually aftermarket products which are certified as R-134a compatible. Some car manufacturers offer OEM replacement options for older R-12 air conditioning systems.

[edit] Gallery

Time-series of atmospheric concentrations of CFC-12 (Walker et al., 2000)

"Present day" (1990s) sea surface CFC-12 concentration

"Present day" (1990s) CFC-12 oceanic vertical inventory

[edit] External links

[edit] References

^ The Ozone Hole-The Montreal Protocol on Substances that Deplete the Ozone Layer

[0] The Ozone Hole-The Montreal Protocol on Substances that Deplete the Ozone Layer

[1]

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