A student performed the reaction between hydrochloric acid and zinc by two methods.
Method 1: Hydrochloric acid was made to react with zinc powder.
Method 2: Hydrochloric acid was made to react with zinc piece.
The student observed that the rate of reaction was much faster in case of method 1. Which of the following factor most probably had an influence on the rate of the reaction?
(i) The concentration of the reactants- The rate of the reaction increases with the increase in the concentration. Here, zinc powder and a piece of zinc are of the same concentration so concentration is not the factor which is affecting the rate of the reaction.
(ii) The pressure of the gases- The rate of the reaction increases if the pressure on the reacting gases is increased. Here, zinc metal is not in gaseous form, so, pressure will not have any influence on the rate of the reaction.
(iii) The temperature of the reaction- The rate of the reaction increases if the temperature of the reactants is increased. Here, the reactants are at the same temperature, so, temperature will not have any influence on the rate of the reaction.
(iv) The surface area of the reactants- The factor which is affecting the rate of the reaction here is the surface area of the reactant as powdered zinc has more surface area exposed for the reaction to occur. Hence the speed of reaction is faster in the case of powdered zinc.