This textbook covers the thermodynamics needed by chemical engineers both in their engineering and in their chemistry; it is intended for use in all undergraduate and some graduate-level courses. The authors emphasize a rigorous yet concise presentation of the fundamental chemical concepts governing the behavior of single and multicomponent mixtures, including phase and chemical equilibria. In the application of these concepts, consideration is given to the presentation of experimentally measured thermodynamic properties, and to their prediction for real fluids and their mixtures using methods founded on statistical mechanics. Several applications involving the transfer of heat and work that are of special importance to chemical engineers are studied in detail to show the use of thermodynamics in improving performance. The book is written in SI units and contains worked examples, exercises, and problems.