This widely acclaimed text, now in its fifth edition and translated into many languages, continues to present a clear, simple and concise introduction to chemical thermodynamics. An examination of equilibrium in the everyday world of mechanical objects provides the starting point for an accessible account of the factors that determine equilibrium in chemical systems. This straightforward approach leads students to a thorough understanding of the basic principles of thermodynamics, which are then applied to a wide range of physico-chemical systems. The book also discusses the problems of non-ideal solutions and the concept of activity, and provides an introduction to the molecular basis of thermodynamics. Over five editions, the views of teachers of the subject and their students have been incorporated. The result is a little more rigour in specifying the dimensions within logarithmic expressions, the addition of more worked examples and the inclusion of a simple treatment of the molecular basis of thermodynamics. Students on courses in thermodynamics will continue to find this popular book an excellent introductory text.