The surface area of magnesium metal has a significant impact on the reaction rate with hydrochloric acid. The reaction between magnesium metal Mg and hydrochloric acid HCl produces magnesium chloride MgCl2 and hydrogen gas H2 . The reaction can be represented by the following balanced chemical equation:Mg s + 2HCl aq MgCl2 aq + H2 g The reaction rate depends on the frequency of collisions between the reacting particles, in this case, magnesium atoms and hydrochloric acid molecules. When the surface area of magnesium metal is increased, more magnesium atoms are exposed to the hydrochloric acid, leading to a higher frequency of collisions between the reactants.In other words, a larger surface area allows more magnesium atoms to come into contact with hydrochloric acid molecules simultaneously, which increases the reaction rate. This can be observed when using magnesium in different forms, such as a solid block, thin strips, or powder. The powdered form, having the highest surface area, will react the fastest with hydrochloric acid, while the solid block, with the lowest surface area, will react the slowest.In summary, an increase in the surface area of magnesium metal leads to an increase in the reaction rate with hydrochloric acid due to a higher frequency of collisions between the reacting particles.