Chlorodifluoromethane
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| Chlorodifluoromethane | |
|---|---|
  |
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| General | |
| Systematic name | Chlorodifluoromethane |
| Other names | Difluoromonochloromethane HCFC-22 R-22 halocarbon R22 Freon 22 Red Gas |
| Molecular formula | CHClF2 |
| SMILES | ClC(F)F |
| Molar mass | 86.48 g/mol |
| Appearance | Colorless gas. |
| CAS number | [] |
| Properties | |
| Density and phase | 1413 kg/m3 at -41°C, liquid. 4.706 kg/m3 at -41°C, gas. 3.66 kg/m3 at 15°C, gas. |
| Solubility in water | 0.7799 vol/vol (25°C) |
| Melting point | -175.42°C (97.73 K) |
| Boiling point | -40.7 C (232.45 K) |
| Viscosity | 12.56 µPa·s at 0°C |
| Structure | |
| Coordination geometry |
Tetrahedral. |
| Dipole moment | ? D |
| Hazards | |
| MSDS | External MSDS |
| Main hazards | Central nervous system depressant |
| NFPA 704 |
0
1
1
|
| Flash point | ?°C |
| R/S statement | R: ? S: S23, S24, S25. |
| RTECS number | PA6390000 |
| Related compounds | |
| Related CFCs | Dichlorodifluoromethane dichlorofluoromethane |
| Related compounds | Methane |
| Except where noted otherwise, data are given for materials in their standard state (at 25°C, 100 kPa) Infobox disclaimer and references |
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Chlorodifluoromethane or difluoromonochloromethane is a hydrochlorofluorocarbon (HCFC) with chemical formula CHClF2 and CAS number 75-45-6. It is better known under its code names of HCFC-22, R-22, Halocarbon R22 or Freon 22, and is commonly used in air conditioning applications, such as rooftop units and window air conditioners. Under the name Red Gas it is used as a propellant for some airsoft guns.
Chlorodifluoromethane was first used as an alternative to the ozone depleting CFC-11 and CFC-12, but was later decided to be not environmentally friendly enough, although its ozone depletion potential is 0.05, among the lowest for chlorine-containing haloalkanes. It will be phased out soon under the Montreal Protocol, to be replaced by more environmentally friendly refrigerants such as R-410A (an azeotropic mixture of difluoromethane and pentafluoroethane), R-134A (1-1-1-2 tetrafluroethane) and R-409C.
It is an intermediate in the synthesis of tetrafluoroethylene, into which it is converted by pyrolysis. Difluorocarbene is an intermediate in this reaction. The compound also yields difluorocarbene upon treatment with strong base and is used in the laboratory as a source of this reactive intermediate.
[edit] Physical Properties
- Liquid/gas equivalent (101.3 kPa and 15 °C (59 °F)): 385 vol/vol
- Latent heat of vaporization (101.3 kPa at boiling point): 233.95 kJ/kg
- Critical temperature: 96 °C
- Critical pressure: 4.936 MPa
- Compressibility Factor (Z) (101.3 kPa and 15 °C (59 °F)): 0.9831
- Specific gravity (air = 1) (101.3 kPa and 21 °C (70 °F)): 3.08
- Specific volume (101.3 kPa and 21 °C (70 °F)): 0.275 m³/kg
- Heat capacity at constant pressure (Cp) (101.3 kPa and 30 °C (86 °F)): 0.057 kJ/(mol·K)
- Heat capacity at constant volume (Cv) (101.3 kPa and 30 °C (86 °F)): 0.048 kJ/(mol·K)
- Ratio of specific heats (γ=Cp/Cv) (101.3 kPa and 30 °C (86 °F)) : 1.178253
