The reaction between hydrochloric acid HCl and magnesium ribbon Mg can be represented by the following balanced chemical equation:Mg s + 2 HCl aq MgCl2 aq + H2 g The effect of pH on the reaction rate between hydrochloric acid and magnesium ribbon can be understood by considering the concentration of H+ ions in the solution. The pH of a solution is a measure of the concentration of H+ ions, with lower pH values indicating higher concentrations of H+ ions and higher pH values indicating lower concentrations of H+ ions.In the case of the reaction between HCl and Mg, the concentration of H+ ions in the solution directly affects the reaction rate. As the concentration of H+ ions increases lower pH , the reaction rate also increases. This is because there are more H+ ions available to react with the magnesium ribbon, leading to a faster rate of reaction.Conversely, as the concentration of H+ ions decreases higher pH , the reaction rate decreases. This is because there are fewer H+ ions available to react with the magnesium ribbon, leading to a slower rate of reaction.In summary, the effect of pH on the reaction rate between hydrochloric acid and magnesium ribbon is that a lower pH higher H+ ion concentration will result in a faster reaction rate, while a higher pH lower H+ ion concentration will result in a slower reaction rate.