3D model (JSmol)
|Molar mass||53.9962 g/mol|
|Appearance||colorless gas, pale yellow liquid when condensed|
|Density||1.90 g/cm3 (-224° C, liquid),|
1.719 g/cm3 (-183° C, liquid), 1.521 g/cm3 (liquid at −145 °C), 1.88 g/l (gas at room temperature)
|Melting point||−223.8 °C (−370.8 °F; 49.3 K)|
|Boiling point||−144.75 °C (−228.55 °F; 128.40 K)|
|Vapor pressure||48.9 atm (at −58.0 °C or −72.4 °F or 215.2 K[a])|
Heat capacity (C)
|43.3 J/mol K|
|246.98 J/mol K|
Std enthalpy of
|24.5 kJ mol−1|
Gibbs free energy (ΔfG˚)
|T+ O C N|
|Lethal dose or concentration (LD, LC):|
LC50 (median concentration)
|2.6 ppm (rat, 1 hr)|
1.5 ppm (mouse, 1 hr)
26 ppm (dog, 1 hr)
16 ppm (monkey, 1 hr)
|US health exposure limits (NIOSH):|
|TWA 0.05 ppm (0.1 mg/m3)|
|C 0.05 ppm (0.1 mg/m3)|
IDLH (Immediate danger)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|what is ?)(|
Oxygen difluoride is the chemical compound with the formula OF2. As predicted by VSEPR theory, the molecule adopts a "bent" molecular geometry similar to that of water, but it has very different properties, being a strong oxidizer.
Oxygen difluoride was first reported in 1929; it was obtained by the electrolysis of molten potassium fluoride and hydrofluoric acid containing small quantities of water. The modern preparation entails the reaction of fluorine with a dilute aqueous solution of sodium hydroxide, with sodium fluoride as a side-product:
- 2 F2 + 2 NaOH → OF2 + 2 NaF + H2O
Its powerful oxidizing properties are suggested by the oxidation number of +2 for the oxygen atom instead of its normal −2. Above 200 °C, OF2 decomposes to oxygen and fluorine via a radical mechanism.
OF2 reacts with many metals to yield oxides and fluorides. Nonmetals also react: phosphorus reacts with OF2 to form PF5 and POF3; sulfur gives SO2 and SF4; and unusually for a noble gas, xenon reacts, at elevated temperatures, yielding XeF4 and xenon oxyfluorides.
Oxygen difluoride reacts very slowly with water to form hydrofluoric acid:
- OF2 (aq) + H2O (l) → 2 HF (aq) + O2 (g)
- OF2 + SO2 → SO3 + F2
- OF2 + 2 SO2 → S
This section needs expansion. You can help by adding to it. (August 2018)
Oxygen difluoride is considered an unsafe gas due to its oxidizing properties.
In Robert L. Forward's science fiction novel Camelot 30K, oxygen difluoride was used as a biochemical solvent by fictional life forms living in the solar system's Kuiper belt. While OF
2 would be a solid at 30 K, the fictional alien lifeforms were described as endothermic, maintaining elevated body temperatures and liquid OF
2 blood by radiothermal heating.
- "difluorine monoxide;oxygen difluoride,physical properties,suppliers,CAS,MSDS,structure,Molecular Formula, Molecular Weight ,Solubility,boiling point, melting point". www.chemyq.com.
- NIOSH Pocket Guide to Chemical Hazards. "#0475". National Institute for Occupational Safety and Health (NIOSH).
- "Oxygen difluoride". Immediately Dangerous to Life and Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
- Lebeau, P.; Damiens, A. (1929). "Sur un nouveau mode de préparation du fluorure d'oxygène" [A new method of preparation of oxygen fluoride]. Comptes rendus hebdomadaires des séances de l'Académie des Sciences (in French). 188: 1253–1255. Retrieved February 21, 2013.
- Lebeau, P.; Damiens, A. (1927). "Sur l'existence d'un composé oxygéné du fluor" [The existence of an oxygen compound of fluorine]. Comptes rendus hebdomadaires des séances de l'Académie des Sciences (in French). 185: 652–654. Retrieved February 21, 2013.