In this and the next two chapters we will study thermodynamics. Thermodynamics is the study of the thermal energy. Thermodynamics is a very important branch of science and engineering.  For example, chemists need it to optimize certain products of chemical reactions, chemical engineers use thermodynamics in their designs of chemical plants, mechanical engineers implement laws of thermodynamics to design effective engines and refrigerators, and architects need to understand basic heat transfer mechanism to insulate and save in cooling or heating buildings.

3-1 Introduction