Investigation of the equilibrium of pyridine protonization by adsorption measurements

Abstract

The double-layer capacitance of a mercury electrode in the solutions containing pyridine at different pH was measured. From the dependence of capacitance on pH the p K of pyridine was determined. This p K obtained for different potentials of the electrode characterizes the acid-base properties of pyridine in the field of the electrode. The p K of pyridine was also calculated (a) using the Frumkin isotherm and calculated adsorption parameters and (b) from the dependence of the pzc of the mercury electrode in pyridine solutions on pH. The p K values obtained are in good agreement with data reported in the literature.