Difluorophosphoric acid
| Names | |
|---|---|
| IUPAC name
Difluorophosphinic acid | |
Other names
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| Identifiers | |
3D model (JSmol) |
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| ChemSpider | |
| ECHA InfoCard | 100.034.005 |
| EC Number |
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PubChem CID |
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| UNII | |
| UN number | 1768 |
CompTox Dashboard (EPA) |
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| Properties | |
| HPO2F2 | |
| Molar mass | 101.977 g·mol−1 |
| Appearance | Colorless liquid |
| Density | 1.583 g/cm3 |
| Melting point | −96.5 °C (−141.7 °F; 176.7 K) |
| Boiling point | 115.9 °C (240.6 °F; 389.0 K) |
| Structure | |
| Tetrahedral at phosphorus atom | |
| Hazards | |
| Occupational safety and health (OHS/OSH): | |
Main hazards |
Corrosive to living tissue |
| GHS labelling: | |
| Danger | |
| H314 | |
| P260, P264, P280, P301+P330+P331, P303+P361+P353, P304+P340, P305+P351+P338, P310, P321, P363, P405, P501 | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references | |
Difluorophosphoric acid is an inorganic compound with the formula HPO2F2. It is a mobile colorless strongly fuming liquid. The acid has limited applications, in part because it is thermally and hydrolytically unstable. Difluorophosphoric acid is corrosive to glass, fabric, metals and living tissue.
A method to make pure difluorphosphoric acid involves heating phosphoryl fluoride with fluorophosphoric acid and separating the product by distillation:
- POF3 + H2PO3F → 2 HPO2F2
It is prepared by hydrolysis of phosphoryl fluoride:
- POF3 + H2O → HPO2F2 + HF
Further hydrolysis gives fluorophosphoric acid:
- HPO2F2 + H2O → H2PO3F + HF
Complete hydrolysis gives phosphoric acid:
- H2PO3F + H2O → H3PO4 + HF
The salts of difluorophosphoric acid are known as difluorophosphates.