Which factors should be altered in chemical reaction between zinc (s) and hydrochloric acid (l) in order to speed up the rate of reaction?

Increasing acid concentration- increased number of reactant particles means they are more crowded so there is a greater chance of the particles collidingIncreasing temperature- reactant particles have more energy therefore move more and collide more often-more of the collisions result in a reaction. Using powdered zinc instead of lumps- increasing the surface area means more zinc particles come into contact with the acid.