Changing the reactant concentrations in a chemical reaction can significantly affect the rate of reaction, but it does not affect the reaction stoichiometry. The rate of reaction is influenced by the concentration of reactants because, in general, a higher concentration of reactants leads to more frequent collisions between particles, which in turn leads to a faster reaction rate. This relationship is described by the rate law, which is determined experimentally.The reaction between potassium iodide KI and hydrogen peroxide H2O2 can be used as an example to demonstrate the effect of reactant concentrations on the rate of reaction. The reaction can be represented by the following equation:2 KI aq + H2O2 aq 2 KI aq + 2 H2O l + O2 g In this reaction, iodide ions I- react with hydrogen peroxide to produce water, oxygen gas, and iodine ions I2 . The rate law for this reaction can be determined experimentally and is found to be:Rate = k [KI]^x [H2O2]^ywhere k is the rate constant, x and y are the orders of the reaction with respect to KI and H2O2, respectively, and [KI] and [H2O2] are the concentrations of KI and H2O2, respectively.To provide experimental evidence for the effect of reactant concentrations on the rate of reaction, you can perform a series of experiments in which you vary the initial concentrations of KI and H2O2 while keeping other factors such as temperature and pressure constant. You can then measure the rate of reaction by monitoring the production of oxygen gas or the disappearance of one of the reactants e.g., H2O2 over time.The results of these experiments will likely show that the rate of reaction increases as the concentration of either KI or H2O2 is increased. This supports the idea that the rate of reaction is dependent on the concentration of reactants.However, changing the reactant concentrations does not affect the reaction stoichiometry, which is determined by the balanced chemical equation. The stoichiometry of a reaction describes the mole-to-mole relationship between the reactants and products, and it remains constant regardless of the reactant concentrations. In the case of the reaction between KI and H2O2, the stoichiometry indicates that two moles of KI react with one mole of H2O2 to produce two moles of KI, two moles of H2O, and one mole of O2. This stoichiometric relationship will not change even if the initial concentrations of KI and H2O2 are varied.