For each experiment, independent titrations of strong acid solutions with standard base were carried out under the same medium and ionic strength as the systems to be investigated, with the aim of determining the electrode potential (E 0 ) using the GLEE software. For each titration, 80 to 100 data points were collected, and the equilibrium state during titrations was checked by confirming the time required to reach equilibrium. All the potentiometric titrations were made over the pH range 3 to 10.