Changing the reaction stoichiometry affects the rate of a chemical reaction between hydrogen peroxide H2O2 and potassium iodide KI by altering the concentrations of the reactants, which in turn influences the reaction rate according to the rate law.The reaction between hydrogen peroxide and potassium iodide can be represented by the following equation:2 H2O2 aq + 2 KI aq 2 H2O l + 2 KI aq + O2 g The rate law for this reaction is given by:Rate = k [H2O2]^m [KI]^nwhere k is the rate constant, m and n are the reaction orders with respect to hydrogen peroxide and potassium iodide, respectively, and [H2O2] and [KI] are the concentrations of hydrogen peroxide and potassium iodide, respectively.When you change the stoichiometry of the reaction, you are essentially changing the ratio of the reactants. This can be done by either increasing or decreasing the concentration of one or both reactants. As a result, the rate of the reaction will be affected according to the rate law.For example, if you increase the concentration of hydrogen peroxide while keeping the concentration of potassium iodide constant, the rate of the reaction will increase if the reaction order m is positive. Similarly, if you increase the concentration of potassium iodide while keeping the concentration of hydrogen peroxide constant, the rate of the reaction will increase if the reaction order n is positive.In summary, changing the reaction stoichiometry affects the rate of a chemical reaction between hydrogen peroxide and potassium iodide by altering the concentrations of the reactants, which in turn influences the reaction rate according to the rate law. The exact effect on the reaction rate will depend on the specific changes made to the stoichiometry and the reaction orders with respect to the reactants.