ABSTRACT
This chapter shows how the free energies of mixtures depend on the concentrations of the various species, and how these concentration dependences determine the thermodynamics of mixing and of chemical reactions. The chemical potential varies logarithmically with concentration. The chapter explains chemical potentials of species that are combined in various proportions. The chemical potential varies logarithmically with concentration. In the process of deriving this logarithmic dependence, the chapter introduces the concept of "standard state" concentrations. A key concept that emerges from the reaction free energy equation is the equilibrium constant. The chapter discusses the relationship between the equilibrium constant and the standard state, and how the equilibrium constant depends on temperature and pressure. Before tackling the concentration dependence of chemical potentials and the total Gibbs free energy, the chapter also introduces the different concentration scales that are used in thermodynamics.
