
Fluorophosphoric acid

Fluorophosphoric acid is the inorganic compound with the formula H2PO3F. It is a colorless viscous liquid that solidified to a glass upon cooling. 
Preparation.
Fluorophosphoric acid is produced commercially by treating phosphorus pentoxide with hydrogen fluoride. A less pure product can also be prepared by hydrolysis of phosphorus oxyfluoride, a reaction that first produces difluorophosphoric acid: 
The next steps give monofluorophosphoric acid:
Reactions.
Fluorophosphoric acid is a dibasic acid, with pKas of 5.5 and around 8.5. The conjugate bases are the monofluorophosphates, which are hydrolytically robust.