This chapter begins by defining a spontaneous process. After a review of enthalpy, it introduces the concept of entropy and its effect on the spontaneity of reactions. It also explains the relationship between spontaneity and free energy.

In this chapter, you will learn: to explain what is meant by a spontaneous process to relate enthalpy changes to spontaneity to define entropy to state the entropy criterion for a spontaneous process to state the criterion for reaction spontaneity in terms of its free energy change