Fluoroform
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| Names | |||
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IUPAC name
Trifluoromethane
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| Other names
Fluoroform, Carbon trifluoride, Methyl trifluoride, Fluoryl, Freon 23, Arcton 1, HFC 23, R-23, FE-13, UN 1984
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| Identifiers | |||
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3D model (Jmol)
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| ChEBI | |||
| ChemSpider | |||
| ECHA InfoCard | 100.000.794 | ||
| EC Number | 200-872-4 | ||
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PubChem CID
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| RTECS number | PB6900000 | ||
| UNII | |||
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| Properties | |||
| CHF3 | |||
| Molar mass | 70.01 g/mol | ||
| Appearance | Colorless gas | ||
| Density | 2.946 kg·m−3 (gas, 1 bar, 15 °C) | ||
| Melting point | −155.2 °C (−247.4 °F; 118.0 K) | ||
| Boiling point | −82.1 °C (−115.8 °F; 191.1 K) | ||
| 1 g/l | |||
| Solubility in organic solvents | Soluble | ||
| Vapor pressure | 4.38 MPa at 20 °C | ||
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Henry's law
constant (kH) |
0.013 mol.kg−1.bar−1 | ||
| Acidity (pKa) | 25 - 28 | ||
| Structure | |||
| Tetrahedral | |||
| Hazards | |||
| Main hazards | Nervous system depression | ||
| S-phrases | S38 | ||
| NFPA 704 | |||
| Flash point | Non-flammable | ||
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Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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 (what is   ?) |
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| Infobox references | |||
Fluoroform is the chemical compound with the formula CHF3. It is one of the "haloforms", a class of compounds with the formula CHX3 (X = halogen). Fluoroform is used in diverse niche applications and is produced as a by-product of the manufacture of Teflon. It is also generated biologically in small amounts apparently by decarboxylation of trifluoroacetic acid.
The molecule adopts tetrahedral molecular geometry with C3vsymmetry.
Fluoroform was first obtained by Maurice Meslans in the violent reaction of iodoform with dry silver fluoride in 1894. The reaction was improved by Otto Ruff by substitution of silver fluoride by a mixture of mercury fluoride and calcium fluoride. The exchange reaction works with iodoform and bromoform, and the exchange of the first two halogen atoms by fluorine is vigorous. By changing to a two step process, first forming a bromodifluoro methane in the reaction of antimony trifluoride with bromoform and finishing the reaction with mercury fluoride the first efficient synthesis method was found by Henne.
CHF3 is used in the semiconductor industry in plasma etching of silicon oxide and silicon nitride. Known as R-23 or HFC-23, it is also a useful refrigerant, sometimes as a replacement for chlorotrifluoromethane (cfc-13) and is a byproduct of its manufacture.
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