The preparation of this second edition is motivated by the effectiveness of the first edition in classroom instruction, so the original structure and content have been retained. Our changes have been directed to the needs of students and other readers. Most obviously, we have moved the review of mathematics, formerly an appendix, to the front of the book (and, by labeling it Chapter 0, have conveniently preserved the structure and numbering throughout the following body of the text). We have added new textual material and figures in several places, most notably in Chapter 14, the chapter treating noncovalent chemical interactions; it is this chapter that most clearly distinguishes the content of this book from that of other thermodynamic texts. Two new appendices provide ancillary material that expands certain matters bordering the subject of classical thermodynamics.