ABSTRACT
The notion of a potential plays a very important role in mechanics. Even without solving dynamical equations like for example the Isaac Newton’s laws, a knowledge of even the gross features of a potential, like its maxima or minima, tells us about special configurations called the stable points. One may hope that in equilibrium thermodynamics too there would be analogous potentials that would be helpful in identifying equilibrium states. In equilibrium thermodynamics, a state is characterised by some set of independent thermodynamic coordinates like P,T or P,V. So the goal is to find functions of such thermodynamic coordinates whose gross features like minima will identify equilibrium states. Thermodynamic potentials are very powerful, and practically indispensable, tools for a finer understanding of thermodynamics. The reader may find the meaning, and even the usefulness, of the mathematical aspects rather obscure at first. They will become clearer as we go on, and more so after these concepts are repeatedly applied to concrete physical problems.
