Which of the following would increase the rate of a chemical reaction between hydrochloric acid (HCl) and solid zinc metal (Zn) ? A. Decreasing the amount of Zn B. Performing the reaction at a lower temperature C. Pulverizing the zinc metal into a fine powder D. Decreasing the concentration of HCl

C. Pulverizing the zinc metal into a fine powder

Explanation:

Pulverizing the zinc metal into a fine powder would increase the rate of chemical reaction between hydrochloric acid and zinc metal. This can be explained by the fact that pulverizing the zinc metal into fine powder will increase the surface area or the area of contact with the other reactant, HCl, thus making the reaction rate increase. Increase in surface area of the reactant Zinc increases the frequency of collision between the reactant particles, and in turn increasing the rate of reaction.