Difluorophosphoric acid
 | |
| Names | |
|---|---|
| IUPAC name Difluorophosphinic acid[1] | |
Other names
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| Identifiers | |
CAS Number |
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3D model (JSmol) |
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| ECHA InfoCard | 100.034.005  |
| EC Number |
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PubChem CID |
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| UNII |
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| UN number | 1768 |
CompTox Dashboard (EPA) |
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InChI
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| Properties | |
Chemical formula | HPO2F2 |
| Molar mass | 101.977 g·mol−1 |
| Appearance | Colorless liquid[1] |
| Density | 1.583 g/cm3[1][2] |
| Melting point | −96.5 °C (−141.7 °F; 176.7 K)[2] |
| Boiling point | 115.9 °C (240.6 °F; 389.0 K)[2] |
| Structure | |
Molecular shape | Tetrahedral at phosphorus atom |
| Hazards | |
| Occupational safety and health (OHS/OSH): | |
Main hazards | Corrosive to living tissue |
| GHS labelling: | |
Pictograms |  |
| 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 | |
Chemical compound
Difluorophosphoric acid is an inorganic compound with the formula HPO2F2. It is a mobile colorless strongly fuming liquid.[1] The acid has limited applications, in part because it is thermally and hydrolytically unstable.[3] Difluorophosphoric acid is corrosive to glass, fabric, metals and living tissue.[1]
A method to make pure difluorphosphoric acid involves heating phosphoryl fluoride with fluorophosphoric acid and separating the product by distillation:[4]
- 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.
References
- ^ a b c d e f g h https://pubchem.ncbi.nlm.nih.gov/compound/Difluorophosphoric-acid
- ^ a b c Reed, William (September 1965). Studies of Difluorophosphoric Acid and its Alkali Metal Salts (Thesis). Retrieved 23 April 2023.
- ^ Charles B. Lindahl; Tariq Mahmood (2000). "Fluorine Compounds, Inorganic, Phosphorus". Kirk‐Othmer Encyclopedia of Chemical Technology. doi:10.1002/0471238961.1608151912091404.a01. ISBN 0-471-23896-1.
- ^ Lange, Willy; Livingston, Ralph (March 1950). "Studies of Fluorophosphoric Acids and their Derivatives. XIV. Preparation of Anhydrous Difluorophosphoric Acid". Journal of the American Chemical Society. 72 (3): 1280–1281. doi:10.1021/ja01159a057.
