Introduction to Entropy and Second Law
The section is centered on the explanation of the entropy concept. The author starts by analyzing the mixing of two gases at the same temperature and pressure, and then, the meaning of what is a function of state is explained in reference to the entropy. The focus of this chapter is on the statistical derivation of the concept of entropy; this is done by means of the particles model. Additional remarks are given on entropy and chemical reactions, and one definition of the second law of thermodynamics is given in reference to the Kelvin–Planck statement. Finally, notions of entropy balances are given.