A simple theoretical model to describe equilibrium properties of homogeneous reversible chemical reactions is proposed and applied to an A ? B type reaction. Forthis purpose the equilibrium properties are analyzed by usual Monte Carlo simulation. It is shown that the equilibrium constant (Ke) for this kind of reaction exhibitsdistinct characteristics for Eba < 1, Eba = 1 and Eba > 1, where Eba is the ratio between the reverse and forward activation energies. For Eba < 1 (Eba > 1) and increase(decrease) the temperature our results recover the principle of Le Ch?atelier appliedto temperature effects. The special and interesting case is obtained for Eba = 1 sinceKe = 1 for all range of temperature. Another important parameter in our analysisis θA, defined as temperature measured with relation the activation energy of theforward reaction. For fixed values of Eba and for θA ? 1 the equilibrium constantapproaches 1, showing that all transitions are equally likely, no matter the differencein the energy barriers. The data obtained in our simulations show the well knownrelationship between Ke, Eb, Ea and kBT . Finally we argue that this theoreticalmodel can be applied to a family of homogeneous chemical reactions characterizedby the same Eba and θA showing the broad application of this stochastic model tostudy chemical reactions. Some of these results will be discussed in terms of collisiontheory.
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