The reaction between hydrochloric acid HCl and magnesium metal Mg can be represented by the following balanced chemical equation:Mg s + 2 HCl aq MgCl2 aq + H2 g The reaction rate of this reaction depends on several factors, including the concentration of hydrochloric acid. According to the collision theory, the reaction rate increases when the concentration of the reactants increases because there are more particles in the same volume, leading to a higher chance of successful collisions between the reactant particles.In the case of the reaction between hydrochloric acid and magnesium metal, as the concentration of hydrochloric acid increases, the number of HCl molecules in the solution increases. This leads to a higher probability of collisions between HCl molecules and magnesium atoms on the surface of the metal, resulting in an increased reaction rate.However, it is important to note that the relationship between the concentration of hydrochloric acid and the reaction rate may not be linear. As the concentration of HCl increases, the reaction rate may reach a maximum value, after which further increases in concentration will not significantly affect the reaction rate. This can be due to factors such as the limited surface area of the magnesium metal or other factors affecting the reaction kinetics.In summary, the reaction rate between hydrochloric acid and magnesium metal generally increases as the concentration of hydrochloric acid increases, due to a higher probability of successful collisions between reactant particles. However, the relationship may not be linear, and other factors may also influence the reaction rate.