As a chemist, I can explain the effect of changing the concentration of the catalyst on the rate of the catalytic reaction between hydrogen peroxide H2O2 and potassium iodide KI .In this reaction, potassium iodide acts as a catalyst, which means it speeds up the reaction without being consumed in the process. The reaction can be represented as follows:H2O2 aq + 2 KI aq 2 H2O l + I2 aq + 2 K+ aq The rate of a catalytic reaction is directly proportional to the concentration of the catalyst. This means that as the concentration of the catalyst potassium iodide increases, the rate of the reaction between hydrogen peroxide and potassium iodide will also increase, up to a certain point.However, it is important to note that increasing the concentration of the catalyst will only increase the reaction rate until all the active sites on the catalyst are occupied. Beyond this point, further increasing the concentration of the catalyst will not have any significant effect on the reaction rate, as there will be no more available active sites for the reactants to interact with.In summary, increasing the concentration of the catalyst potassium iodide in the reaction between hydrogen peroxide and potassium iodide will increase the rate of the reaction, but only up to a certain point. Beyond that point, the reaction rate will no longer be significantly affected by the catalyst concentration.