Thermodynamics of Natural Systems

Based on inadequate evidence, my own experience, I venture to suggest that the most avid readers of textbooks are the writers of textbooks. This is because writers have to make many choices in presenting any subject, and it is natural to wonder how others have done it. Naturally, after extensive reading, every writer concludes that he or she can do it better in some respect, otherwise why do it? It usually is not difficult to find reasons to think that one can do it better. For one thing, science has become highly specialized, and there are many such specialized subjects which use thermodynamics in their special ways. For another thing,Almost all books on thermodynamics contain some errors which are not purely typographical (Reiss, 1965, Preface, p. ix.)and so authors, myself included, write books which avoid those errors, and commit different ones.This book is written for people more or less like myself; those interested primarily not in chemistry but in some aspect of Earth science, especially an aspect involving aqueous solutions. The level of presentation is difficult to define. The book includes almost all the material from the first edition, which was intended as an introduction for second year undergraduates, so selected portions might still be used at that level. However, it now also includes much of the material from a previous book by Dave Crerar and me1 so it is now suitable for a more advanced course for senior undergraduates or graduate students. All this material has been rewritten and expanded with many examples.Using thermodynamics and understanding it are two different things, and most of the difficulty in writing about the subject lies in explaining the fun­damentals. Just where do all these differential equations come from, and why are such strange concepts useful in real life? There is a persistent trend among authors to see thermodynamics as an experimental science, understood by con­sidering engines, salt solutions, rocks, and so on. In my view it is not. It is a