The Arrhenius equation is one of the most important equations in chemical kinetics and has been discussed by scientists for more than a century since its establishment. The historical process of the equation and further explanations of its relationship with the van't Hoff equation are traced. The physical meaning of the Tolman activation energy is discussed with some suggested modifications. The variation of the activation energy with temperature is discussed, and the temperature range for applying the Arrhenius equation is quantitatively analyzed. It is suggested that the three-constant equation be used even in the normal temperature range for reactants with a complex molecular structure. The similarity between some thermodynamic equations and the Arrhenius equation in physical chemistry textbooks are explained. These discussions will help with correctly understanding and applying the Arrhenius equation.

Keywords： Arrhenius equation ; Tolman activation energy ; Temperature validity range ; Thermodynamic relation