Standardization of potentiometric sensors and acid–base behaviour of a series of bases in nitrobenzene Original Research Article

The dissociation constant of picric acid in nitrobenzene, pKa = 6.63, was established spectrophotometrically, and the standardization of potentiometric systems in this medium using picric acid titration is proposed as a standard method. The acid–base equilibria of a series of bases in nitrobenzene were also studied. The pKHB+ values of the protonated bases of various structure were determined and compared with the pKHB+ values in water and acetonitrile in order to evaluate the resolution of acid strength in these media.