Perfluoropropionic acid

Perfluoropropionic acid or pentafluoropropionic acid is an ultra-short chain perfluoroalkyl carboxylic acid with the formula CF₃CF₂CO₂H. It is a colorless liquid that is strongly acidic. It soluble in both water and polar organic solvents. The compound is produced by electrochemical fluorination of the carboxylic acid or its acid fluoride derivative.
It has a predicted pK_a of 0.38, with an uncertainty of 0.10. In many ways, it is comparable to trifluoroacetic acid.

Occurrence and use

The perfluoropropanoate form has been found in environmental samples.
A convenient laboratory method for generating tetrafluoroethylene is the pyrolysis of the sodium salt of pentafluoropropionic acid: