The iodine clock reaction is a classic chemical reaction involving the reaction between potassium iodide KI and hydrogen peroxide H2O2 in the presence of an acid, usually sulfuric acid H2SO4 . The reaction produces iodine I2 , which then reacts with starch to form a blue-black complex, indicating the end of the reaction.The effect of changing the concentration of reactants on the rate of the iodine clock reaction can be explained using the collision theory and the rate law. According to the collision theory, the rate of a reaction depends on the frequency of effective collisions between reactant molecules. Increasing the concentration of reactants increases the number of molecules in the solution, leading to more frequent collisions and thus a faster reaction rate.The rate law for the iodine clock reaction can be expressed as:Rate = k [KI]^m [H2O2]^nwhere Rate is the reaction rate, k is the rate constant, [KI] and [H2O2] are the concentrations of potassium iodide and hydrogen peroxide, respectively, and m and n are the reaction orders with respect to KI and H2O2.The effect of changing the concentration of potassium iodide KI and hydrogen peroxide H2O2 on the rate of the iodine clock reaction can be summarized as follows:1. Increasing the concentration of potassium iodide KI : If the reaction order with respect to KI m is positive, increasing the concentration of KI will increase the reaction rate. This is because more iodide ions are available to react with hydrogen peroxide, leading to more frequent collisions and a faster reaction.2. Increasing the concentration of hydrogen peroxide H2O2 : If the reaction order with respect to H2O2 n is positive, increasing the concentration of H2O2 will also increase the reaction rate. This is because more hydrogen peroxide molecules are available to react with potassium iodide, leading to more frequent collisions and a faster reaction.In summary, changing the concentration of reactants in the iodine clock reaction will affect the reaction rate. Generally, increasing the concentration of either potassium iodide or hydrogen peroxide will lead to an increase in the reaction rate, assuming positive reaction orders for both reactants. The exact relationship between the concentration changes and the rate changes depends on the reaction orders m and n in the rate law.