The presence of reaction intermediates can significantly affect the rate of a chemical reaction. Reaction intermediates are short-lived, high-energy species that are formed during the course of a reaction but are not present in the final products. They are involved in the elementary steps of a reaction mechanism, and their concentration can influence the overall reaction rate.A specific example of a reaction with reaction intermediates is the reaction between hydrogen and iodine to form hydrogen iodide:H2 + I2 2HIThis reaction occurs via a two-step mechanism involving the formation of a reaction intermediate:Step 1: H2 2H homolytic cleavage of H2 Step 2: H + I2 2HI formation of HI In this reaction, the hydrogen atom H is the reaction intermediate. It is formed in the first step and consumed in the second step. The overall reaction rate depends on the concentration of the reaction intermediate H .Now, let's investigate how changes in the concentration of the reaction intermediate H affect the reaction rate. According to the rate law for the second step of the reaction:Rate = k[H][I2]where k is the rate constant, [H] is the concentration of the reaction intermediate hydrogen atom , and [I2] is the concentration of iodine.From this equation, it is evident that the reaction rate is directly proportional to the concentration of the reaction intermediate H . If the concentration of H increases, the reaction rate will also increase, and vice versa.In summary, the presence of reaction intermediates can significantly affect the rate of a chemical reaction. Changes in their concentration can either increase or decrease the reaction rate, depending on the specific reaction mechanism and the role of the intermediate in the reaction.