Potentiometry:

We are going further to discuss how the electromotive force developed in a galvanic cell can be measured using a potentiometer. This technique consists of measuring the potential between any two electrodes immersed in the solution to be analysed.  For measuring the potential, we need two electrodes and the indicator electrode and a reference electrode along with a device called potentiometer. Potentiometric techniques have several applications within the area of analytical chemistry. These methods could be used for selective and direct measurement of analyte concentrations, for determining end point in several types of titrations and for the determination of various types of equilibrium constants.

In this unit, you will know about different category of reference and indicator electrodes, a brief description about instrumentation and potentiometric titrations.

Objectives

After studying this unit, you should be able to:

• explain the principle of potentiometric methods of analysis,
• describes the method of operation of a potentiometer,
• define a few common types of reference and indicator electrodes,
• compute the equilibrium constants from cell potential,
• defines chemical reactions involved in potentiometric titrations,
• explain the principle of potentiometric titration, and
• state the experimental details of neutralisation, redox, precipitation and complexations reactions.