Difluorophosphoric acid - Misplaced Pages

Difluorophosphoric acid
Names

IUPAC name Difluorophosphinic acid
Other names Difluorophosphoric acid Fluophosphoric acid Phosphorodifluoridic acid
Identifiers
CAS Number	13779-41-4
3D model (JSmol)	Interactive image
ChemSpider	55585
ECHA InfoCard	100.034.005
EC Number	237-421-6
PubChem CID	61681
UNII	3QNA5YG39L
UN number	1768
CompTox Dashboard (EPA)	DTXSID6065632
InChI InChI=1S/F2HO2P/c1-5(2,3)4/h(H,3,4)Key: DGTVXEHQMSJRPE-UHFFFAOYSA-N
SMILES OP(=O)(F)F
Properties
Chemical formula	HPO₂F₂
Molar mass	101.977 g·mol
Appearance	Colorless liquid
Density	1.583 g/cm
Melting point	−96.5 °C (−141.7 °F; 176.7 K)
Boiling point	115.9 °C (240.6 °F; 389.0 K)
Structure
Molecular shape	Tetrahedral at phosphorus atom
Hazards
Occupational safety and health (OHS/OSH):
Main hazards	Corrosive to living tissue
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H314
Precautionary statements	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 , 100 kPa). Infobox references

Chemical compound

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.

References

^ "Difluorophosphoric acid".
^ 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. Bibcode:1950JAChS..72.1280L. doi:10.1021/ja01159a057.