ABSTRACT
Consider a gaseous mixture of molecular species that interact to form a reaction product. As discussed in Chapter 7, chemical reactions are conveniently written in the form ∑ =i i ix X 0, where Xi represents a molecular species i and xi the number of molecules of this species involved in a single reaction process. We are interested in the concentrations of the various molecules once equilibrium has been reached at a given temperature and pressure. In the calculation of the partition function for a particular constituent, we assume that the classical ideal gas approximation holds. e fact that the molecules undergo a chemical reaction shows that interactions between molecules are not weak. However, provided the ideal gas equation of state applies to the system, the intermolecular potential is important only for brief periods when molecules collide. e molecules possess, on average, negligible potential energy.
