The dissociation constants of six selected perfluoroalkanoic acids (from perfluoropentanoic to perfluorodecanoic acid) were determined using neutralization potentiometric titration method. The values of determined dissociation constants ranges from pK (a) = 2.17 to 2.44, and they are in partial agreement with published data which have also been reviewed.
The decrease of value of dissociation constant with increasing number of carbon in alkyl chain has been observed. Also, the increase of values of dissociation constants of perfluoroalkanoic acids in comparison with their nonfluorinated analogs has been confirmed.