Changing the concentration of reactants in a chemical reaction can significantly affect the rate of reaction and its sustainability. In the case of the reaction between hydrogen peroxide H2O2 and potassium iodide KI , the reaction can be represented by the following equation:H2O2 aq + 2 KI aq 2 H2O l + 2 KI aq + I2 s The rate of reaction is directly proportional to the concentration of the reactants, according to the rate law. This means that as the concentration of either hydrogen peroxide or potassium iodide increases, the rate of reaction will also increase. This can be explained by the collision theory, which states that the rate of a reaction depends on the frequency of effective collisions between reactant molecules.When the concentration of reactants is increased, there are more particles in the same volume, leading to a higher probability of collisions between the reactant molecules. This results in an increased rate of reaction. However, it is essential to note that the rate of reaction will only increase up to a certain point, after which it will plateau. This is because the reaction rate is also dependent on other factors, such as temperature and the presence of a catalyst.Sustainability in a chemical reaction refers to the ability of the reaction to continue over time. In the case of the reaction between hydrogen peroxide and potassium iodide, increasing the concentration of reactants will lead to a faster rate of reaction, but it will also cause the reactants to be consumed more quickly. This means that the reaction may not be sustainable over a long period, as the reactants will be depleted at a faster rate.To maintain the sustainability of the reaction, it is essential to balance the rate of reaction with the availability of reactants. This can be achieved by carefully controlling the concentration of reactants, as well as other factors such as temperature and the presence of a catalyst. By optimizing these factors, it is possible to achieve a sustainable reaction rate that allows the reaction to continue for an extended period.