A New Approach to Entropy and the Thermodynamic Temperature Scale Lee Hong-Yi Department of Chemical Engineering, Shanghai Second Polytechnic University, No. 900 Zhong Shan Road (north), 200070 Shanghai, China Although entropy is the most important function of the second law of thermodynamics, its introduction is not easy Several approaches to this funkon have been published,cti~hich can roughly be classiiied into two categories. The first category is thorough, but its procedure is complex (1-9. The second is simple, but its logic is ambiguous (6). It seems difficult to reconcile thoroughness with a simple approach. In this work I introduce a rigorous approach to entropy based on simple deduction. The Clausius Inequality From the Clausius statement of the second law, we have
A to state B. Then it returns to its initial state A by a devised reversible path, in a n appositive direction. a t the .. same temperature. irreversible, dQ
reversible -dQ. Figure 1. Acycle at temperature t.
>O,ift.>t = 0 ,i f t , =t
or for an adiabatic pmcess
