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.
Fluorophosphoric acid is produced by treating phosphorus pentoxide with hydrogen fluoride. It can also be prepared by hydrolysis of phosphorus oxyfluoride. The reaction first produces difluorophosphoric acid:
The next steps give monofluorophosphoric acid:
Complete hydrolysis gives phosphoric acid:

Reactions

Fluorophosphoric acid is a dibasic acid, with pKas of 3.5 and around 8.5. The conjugate bases are the monofluorophosphates, which are hydrolytically robust.