Chemical Thermodynamics

Appendix B

Non-equilibrium Thermodynamics or Thermodynamics of Irreversible Processes

B.I.  Introduction

Most of the physicochemical processes like diffusion, conduction of heat or electricity, chemical transformations, etc. are irreversible processes. In chemically reacting systems, the irreversibility arises primarily because the concentrations of constituents are different from that at thermodynamic equilibrium. On the other hand, irreversibility in flow systems, e.g., thermal conduction, electrical conduction, etc., arises because of spatial variations in the intensive properties. Classical thermodynamics is mainly concerned with a study of systems in equilibrium and hence is applicable only to isolated and closed systems. Methods of equilibrium ...