Potentiometry:

This technique involves the measurement of potential at zero current flow. Analytical use of this technique is made in two ways. Within one, known as direct potentiometry, in this technique, we utilize the single measurement of potential and the Nernst Equation is used to relate cell potential to the concentration of analyte. The liquid-junction potentials and activity coefficients influence the value of cell potential. In the other technique, known as potentiometric titration, a set of measured potential is used to detect the changes in concentration that occur at the equivalence point of a titration. In these titrations the change in the potential is of importance and thus the influence of junction potentials and activity coefficients may be ignored. Let us discuss more about these techniques.