Gourt Home::Gourt :: 1,1,1,2-Tetrafluoroethane
| 1,1,1,2-Tetrafluoroethane | |
|---|---|
| General | |
| Systematic name | 1,1,1,2-tetrafluoroethane |
| Other names | Freon 134a HFC-134a R-134a |
| Molecular formula | C2H2F4 |
| SMILES | FC(F)(F)C(F) |
| Molar mass | 102.03 g/mol |
| Appearance | Colorless gas. |
| CAS number | |
| Properties | |
| Density and phase | 0.00425 g/cm3, gas. |
| Solubility in water | Insoluble. |
| Melting point | -103.3°C (169.85 K) |
| Boiling point | -26.08°C (247.07 K) |
| Structure | |
| Molecular shape | Planar. |
| Dipole moment | ? D |
| Hazards | |
| MSDS | External MSDS |
| Main hazards | Asphyxiant. |
| NFPA 704 | |
| Flash point | Non-flammable. |
| R/S statement | R: ? S: , , , . |
| RTECS number | KI8842500 |
| Supplementary data page | |
| Structure and properties | n, εr, etc. |
| Thermodynamic data | Phase behaviour Solid, liquid, gas |
| Spectral data | UV, IR, NMR, MS |
| Related compounds | |
| Other anions | ? |
| Other cations | ? |
| Related refrigerants | Difluoromethane Pentafluoroethane |
| Related compounds | 1,1,2,2,2-pentafluoroethane 2-Chloro- 1,1,1,2-tetrafluoroethane 1,1,1-Trichloroethane |
| Except where noted otherwise, data are given for materials in their standard state (at 25°C, 100 kPa) Chemical infobox | |
Uses
1,1,1,2-Tetrafluoroethane is an inert gas used primarily as a "high-temperature" refrigerant for domestic refrigeration and automobile air conditioners. Other uses include plastic foam blowing, as a cleaning solvents and as a propellant for the delivery of pharmaceuticals (e.g. bronchodilators), canned air, and in air driers, i.e., for removing the moisture from compressed air. Moisture present in compressed air has a harmful effect on pneumatic systems. Tetrafluoroethane has also been used to cool computers in some overclocking attempts.
History
R-134a first appeared in the early 1990s as a replacement for Dichlorodifluoromethane (R-12), which has significant ozone depleting properties. R-134a has been atmospherically modeled for its impact on depleting ozone and as a contributor to global warming. Research suggests that over the past 10 years the concentration of 1,1,1,2-tetrafluoroethane has increased significantly in the Earth atmosphere, has insignificant ozone depletion potential (ozone layer), significant global warming potential and negligible acidification potential (acid rain). 1,1,1,2-Tetrafluoroethane is slowly converted to trifluoroacetic acid through a radical reaction in the upper atmosphere and leads to a detectable amount of several ng/L rain.
Safety
Contact of tetrafluoroethane with flames or hot surfaces (in excess of around 120 °F or 50 °C) may cause vapor decomposition and the emission of toxic gases. Tetrafluoroethane itself has an LC50 (lethal concentration for 50% of subjects) in rats of 1,500 g/m3, making it relatively non-toxic. However, its gaseous form is denser than air, and will displace air in the lungs. This can result in asphyxiation if excessively inhaled. Spray cans containing tetrafluoroethane, when turned upside-down, can become effective freeze sprays. Gases compressed into liquids absorb a lot of energy upon vaporization, so liquid tetrafluoroethane will lower the temperature of objects it comes into contact with as it evaporates.
According to the MSDS, "In a two-year inhalation study, HFC-134a at a concentration of 50,000 ppm, produced an increase in late-occuring benign testicular tumors, testicular hyperplasia and testicular weight."
References
External links
- http://ptcl.chem.ox.ac.uk/MSDS/TE/1,1,1,2-tetrafluoroethane.html
- http://www.inchem.org/documents/cicads/cicads/cicad11.htm
- http://www.rmsgas.com/quickchangemsds.htm
"1,1,1,2-Tetrafluoroethane"