Prof. Newman is considered one of the great chemical engineers of his time. His reputation derives from his mastery of all phases of the subject matter, his clarity of thought, and his ability to reduce complex problems to their essential core elements. He has been teaching undergraduate and graduate core subject courses at the University of California, Berkeley (UC Berkeley), USA, since joining the faculty in 1966. His method is to write out, in long form, everything he expects to convey to his class on a subject on any given day. He has maintained and updated his lecture notes from notepad to computer throughout his career. This book is an exact reproduction of those notes. The book presents concepts needed to define single- and multi-component systems, starting with the Gibbs function. It helps readers derive concepts of entropy and temperature and the development of material properties of pure substances. It acquaints them with applications of thermodynamics, such as cycles, open systems, and phase transitions, and eventually leads them to concepts of multiple-component systems, in particular, chemical and phase equilibria. It clearly presents all concepts that are necessary for engineers.