How do you find a step that has the largest rate constant in the forward reaction? When looking at a potential energy diagram
Am I not right that the PE diagram tells you what energy level must be attained (and the activation energy) to allow a reaction to occur BUT it never tells you the rate
Are you asking about 'rate determining step' in a reaction mechanism... e.g., Sn1 mechanism of t-BuBr?
To find the step that has the largest rate constant in the forward reaction when looking at a potential energy diagram, you need to examine the energy barriers associated with each step.
A potential energy diagram is a graphical representation that shows the energy changes that occur during a chemical reaction. The horizontal axis represents the progress of the reaction, from reactants to products, while the vertical axis represents the energy of the system.
To determine the step with the largest rate constant in the forward reaction:
1. Identify the reactants and products in the reaction. These are typically shown as the starting and ending points on the potential energy diagram.
2. Look for the highest energy barrier, known as the activation energy, on the diagram. The activation energy represents the energy required to initiate the reaction.
3. Identify the step(s) associated with the highest energy barrier. These steps will have the largest activation energy.
4. The rate constant of a reaction step is directly related to its activation energy. The larger the activation energy, the smaller the rate constant. Therefore, the step with the lowest activation energy will have the largest rate constant in the forward reaction.
By visually examining the potential energy diagram and identifying the step(s) with the highest energy barrier, you can determine the step that has the largest rate constant in the forward reaction.