In this work, we analyzed a simple chemical reaction using Fermi-Dirac's entropy defined in terms of the Löwdin's occupation numbers, this definition of entropy has not been applied or explored enough in the field of quantum chemistry, in this regard, Fermi-Dirac's entropy maybe a good option to perform works in which the main purpose will be the study or analysis of the effect of the electron interactions. The results presented in this work were complemented by the analysis of the kinetic energy, potential energy, and the variation of the electric potential, along the reaction path, our results suggest that this entropy can be a useful tool to perform studies on electron interactions.