The reaction between magnesium and hydrochloric acid in aqueous solution can be represented by the following balanced chemical equation:Mg s + 2HCl aq MgCl2 aq + H2 g The reaction rate depends on several factors, including the concentration of the reactants, temperature, and the presence of catalysts. Changing the reaction stoichiometry, or the mole ratio of reactants, can affect the reaction rate by altering the concentration of the reactants.In this reaction, the stoichiometric ratio of magnesium to hydrochloric acid is 1:2. This means that, ideally, for every mole of magnesium, two moles of hydrochloric acid are required for the reaction to proceed to completion.If the mole ratio of reactants is changed, it can affect the reaction rate in the following ways:1. If the mole ratio of magnesium to hydrochloric acid is increased more magnesium is added , the reaction rate may initially increase due to the higher concentration of magnesium. However, once the hydrochloric acid is consumed, the reaction rate will decrease, as there will not be enough hydrochloric acid to react with the excess magnesium. In this case, hydrochloric acid becomes the limiting reactant.2. If the mole ratio of hydrochloric acid to magnesium is increased more hydrochloric acid is added , the reaction rate may not be significantly affected initially, as the magnesium concentration remains the same. However, once the magnesium is consumed, the reaction rate will decrease, as there will not be enough magnesium to react with the excess hydrochloric acid. In this case, magnesium becomes the limiting reactant.It is important to note that increasing the concentration of one reactant while keeping the other constant can lead to an increase in the reaction rate, but only up to a certain point. Once the limiting reactant is consumed, the reaction rate will decrease, regardless of the excess of the other reactant.In summary, changing the reaction stoichiometry mole ratio of reactants can affect the reaction rate of the chemical reaction between magnesium and hydrochloric acid in aqueous solution by altering the concentration of the reactants and determining the limiting reactant. To optimize the reaction rate, it is essential to maintain the stoichiometric ratio of 1:2 for magnesium to hydrochloric acid.