Changing the temperature of a chemical reaction can have a significant effect on the activation energy barrier. The activation energy is the minimum amount of energy required for a reaction to proceed. When the temperature is increased, the average kinetic energy of the molecules also increases, which means that more molecules have enough energy to overcome the activation energy barrier. This results in an increased reaction rate.Computational chemistry and molecular modeling can be used to calculate the activation energy barriers for the same reaction at different temperatures. This can be done using transition state theory TST and molecular dynamics simulations. Here's a general outline of the process:1. Choose a suitable computational method: Select an appropriate level of theory e.g., density functional theory, ab initio methods and basis set for the molecular modeling calculations.2. Model the reactants, products, and transition state: Build the molecular structures of the reactants, products, and the transition state for the reaction. Optimize their geometries and calculate their energies at the chosen level of theory.3. Calculate the activation energy: Determine the energy difference between the transition state and the reactants. This difference corresponds to the activation energy barrier.4. Perform calculations at different temperatures: Repeat steps 2 and 3 for different temperatures. This can be done by running molecular dynamics simulations at various temperatures and extracting the activation energies from the simulations.5. Analyze the results: Compare the activation energy barriers obtained at different temperatures. If the activation energy barrier decreases with increasing temperature, it indicates that the reaction becomes more favorable at higher temperatures.The change in activation energy with temperature can be explained by the Arrhenius equation:k = Ae^-Ea/RT where k is the reaction rate constant, A is the pre-exponential factor, Ea is the activation energy, R is the gas constant, and T is the temperature. As the temperature increases, the exponential term becomes less negative, leading to an increase in the reaction rate constant. This means that the reaction proceeds more quickly at higher temperatures, which is consistent with the observation that activation energy barriers generally decrease with increasing temperature.In conclusion, computational chemistry and molecular modeling can be used to calculate the activation energy barriers for a reaction at different temperatures. The results can provide insights into how the activation energy barrier changes with temperature, which can help in understanding and controlling the reaction rates for various chemical processes.