1.1 Introduction

Physical chemistry is a broad subject and no simple definition can do it justice. For our purposes we can consider physical chemistry as that field that studies the physical laws and processes underlying chemistry.

It is a subject that covers many subjects. Of these our primary concern in this part of the course is classical thermodynamics.

Classical thermodynamics is the study of the thermal properties of chemical systems at equilibrium. It is called classical because it, like geometry, is based on axioms, postulates, and definitions. It is a deductive science whose conclusions hold true in the physical world as long as its axioms and postulates are true in the physical world.

This approach is at once very powerful and very limiting. Classical thermodynamics knows nothing really about atoms and molecules, nothing about quantum mechanics, and nothing about subatomic phenomena at all. On the other hand, classical thermodynamics must be consistent with all of those. And, since they are the most fundamental building blocks of chemistry, it must be possible to deduce classical thermodynamics from them.

And it is. The field that connects quantum mechanics with thermodynamics is called statistical thermodynamics. An introduction to statistical thermodynamics is given in the second term of this course.