Using Computer-Based “Experiments” in the Analysis of Chemical Reaction Equilibria

摘要

The application of the Reaction Monte Carlo (RxMC) algorithm to standard textbook problems in chemical reaction equilibria is discussed. The RxMC method is a molecular simulation algorithm for studying the equilibrium properties of reactive systems, and therefore provides the opportunity to develop computer-based “experiments” for the analysis of a wide range of chemical reactions. As the conditions of the reaction can be precisely controlled in these simulations, students can rather easily perform “virtual experiments”, and then compare the resulting compositions, extents of reaction, etc. with the predictions obtained using the relations of macroscopic thermodynamics. Students can also use these “experiments” to directly test the guidelines suggested by Le Chatelier’s principle, and even study situations in which exceptions to these guidelines are known to occur. These computer-based analyses can therefore be used as the basis of various useful and instructive homework assignments, or group projects, which can also touch upon important topics in molecular thermodynamics. Simulations can be performed on ideal gases (i.e., noninteracting particles), and depending upon the level of the student audience, the simulation algorithms can be modified to describe reactions in nonideal systems, in which the intermolecular potential energies between the molecules need to be considered. Thus, concepts from molecular thermodynamics can also be incorporated into the analyses of chemical reaction equilibria.