In a consecutive also known as sequential mechanism, a chemical reaction occurs in a series of steps, with each step involving a different reaction intermediate. The overall reaction rate depends on the rates of the individual steps. When the reactant concentrations are altered, the rate of the chemical reaction can be affected in various ways, depending on the specific reaction mechanism and the rate-determining step.To understand the effect of altering reactant concentrations on the rate of chemical reactions that follow a consecutive mechanism, let's consider a general two-step reaction:Step 1: A + B C with rate constant k1 Step 2: C + D E with rate constant k2 The overall reaction is: A + B + D C + EFor simplicity, let's assume that step 1 is the rate-determining step, meaning that it is slower than step 2. The rate law for step 1 can be written as:Rate1 = k1[A][B]If we increase the concentration of A or B, the rate of step 1 will increase, leading to a higher overall reaction rate. However, if we increase the concentration of D, it will not have a significant effect on the overall reaction rate, since step 1 is the rate-determining step.Now, let's consider a case where step 2 is the rate-determining step. The rate law for step 2 can be written as:Rate2 = k2[C][D]In this case, increasing the concentration of A or B will not have a significant effect on the overall reaction rate, since step 2 is the rate-determining step. However, increasing the concentration of D will increase the rate of step 2, leading to a higher overall reaction rate.Experimental evidence to support these conclusions can be obtained by monitoring the reaction rate as a function of reactant concentrations. For example, one could measure the rate of product formation E at various concentrations of A, B, and D, and then compare the results to the predictions of the rate laws for the two-step consecutive mechanism.In summary, the effect of altering reactant concentrations on the rate of chemical reactions that follow a consecutive mechanism depends on the specific reaction mechanism and the rate-determining step. By understanding the reaction mechanism and the rate laws for each step, one can predict how changes in reactant concentrations will affect the overall reaction rate. Experimental evidence can then be used to confirm these predictions and further refine our understanding of the reaction mechanism.