???Defining entropy before heat, not viceversa??? in introductory thermodynamics: twentyfive-year teaching experience in engineering programs

As well as many other people, we have felt, both as students and as teachers, that some traditional approaches present ambiguities and logical inconsistencies in the exposition of the basics of thermodynamics. Since the late ???80s we have adopted an approach developed over thirty years of course and research work at M.I.T.: rooted in the work of Hatsopoulos and Keenan [1], it has been presented in a systematic and detailed way by Gyftopoulos and Beretta [2]. On the basis of our teaching experience we believe that this approach is particularly suited for students attending engineering programs and our goal here is to underline the most important reasons of its success. In the paper we summarize and discuss how we have adapted the sequence of arguments proposed in [2, Chaps. 2-14] to meet the needs of undergraduate engineering students. [1] G.N. Hatsopoulos and J.H. Keenan, Principles of General Thermodynamics, Wiley, 1965. [2] E.P. Gyftopoulos and G.P. Beretta, Thermodynamics. Foundations and Applications, Macmillan, 1991, (Dover Edition, 2005).