The change in the stoichiometric ratio of reactants can affect the rate of a chemical reaction in several ways. The stoichiometric ratio refers to the proportion of reactants in a balanced chemical equation, which is necessary for the reaction to proceed to completion. When the stoichiometric ratio is altered, it can lead to the following effects on the reaction rate:1. Optimal ratio: When the stoichiometric ratio of reactants is optimal i.e., exactly as per the balanced chemical equation , the reaction proceeds at its maximum rate. This is because all reactants are present in the correct proportions, allowing them to react efficiently and completely.2. Excess of one reactant: If there is an excess of one reactant, the reaction rate may initially be faster due to the higher concentration of that reactant. However, as the reaction proceeds, the excess reactant will not be consumed as quickly as the limiting reactant the reactant present in a smaller amount . This will cause the reaction rate to slow down as the limiting reactant is depleted.3. Insufficient amount of one reactant: If there is an insufficient amount of one reactant, the reaction rate will be slower than the optimal rate. This is because the limiting reactant will be consumed quickly, and the reaction will not proceed as efficiently as it could with the correct stoichiometric ratio.4. Change in reaction mechanism: In some cases, altering the stoichiometric ratio of reactants can lead to a change in the reaction mechanism, which can affect the reaction rate. This is more common in complex reactions involving multiple steps or intermediates.In summary, maintaining the correct stoichiometric ratio of reactants is crucial for ensuring that a chemical reaction proceeds at its maximum rate. Deviations from the optimal ratio can lead to slower reaction rates or even changes in the reaction mechanism.