How do potential energy diagrams help visualise activation energies?

Potential energy diagrams help visualise activation energies by graphically representing the energy changes during a chemical reaction.

Potential energy diagrams, also known as reaction progress diagrams, are graphical representations that illustrate the energy changes during a chemical reaction. They are particularly useful in visualising the concept of activation energy, which is the minimum amount of energy required for a reaction to occur.

In a potential energy diagram, the horizontal axis represents the progress of the reaction, while the vertical axis represents the potential energy. The reactants and products are represented by points on the diagram, and the difference in their energy levels indicates whether the reaction is exothermic (releases energy) or endothermic (absorbs energy).

The activation energy is represented by the highest point on the diagram, which is the peak of the energy barrier that must be overcome for the reaction to proceed. This peak is often referred to as the transition state or activated complex. The height of this peak relative to the energy level of the reactants visually demonstrates the amount of energy required to initiate the reaction.

In addition, potential energy diagrams can also illustrate the effect of catalysts on activation energy. Catalysts work by providing an alternative reaction pathway with a lower energy barrier. This is represented on the diagram as a lower peak, indicating that less energy is required for the reaction to occur.

Overall, potential energy diagrams provide a clear and intuitive way to understand the concept of activation energy. By visualising the energy changes during a reaction, they allow students to grasp the fundamental principles of chemical kinetics and thermodynamics.