The surface area of a reactant affects the rate of reaction by increasing the number of collisions between reactant particles. When the surface area of a reactant is increased, more particles are exposed and available for collisions with other reactant particles, leading to a higher probability of successful collisions and an increased rate of reaction.Experimental evidence for this can be demonstrated using the reaction between calcium carbonate CaCO3 and hydrochloric acid HCl . In this reaction, calcium carbonate reacts with hydrochloric acid to produce calcium chloride CaCl2 , water H2O , and carbon dioxide CO2 :CaCO3 s + 2 HCl aq CaCl2 aq + H2O l + CO2 g To investigate the effect of surface area on the rate of reaction, we can use three different forms of calcium carbonate with varying surface areas: large marble chips, small marble chips, and powdered calcium carbonate. The surface area increases from large marble chips to small marble chips to powdered calcium carbonate.Experimental Procedure:1. Measure a fixed volume of hydrochloric acid e.g., 50 mL with a known concentration e.g., 1.0 M and pour it into a conical flask.2. Measure a fixed mass of calcium carbonate e.g., 5 g in each of the three forms: large marble chips, small marble chips, and powdered calcium carbonate.3. Add the large marble chips to the hydrochloric acid in the conical flask and start a timer.4. Measure the volume of carbon dioxide gas produced at regular intervals e.g., every 30 seconds using a gas syringe or an inverted measuring cylinder filled with water.5. Repeat steps 1-4 for small marble chips and powdered calcium carbonate.6. Plot the volume of carbon dioxide gas produced against time for each form of calcium carbonate.Results:The results will show that the rate of reaction increases as the surface area of the calcium carbonate increases. The powdered calcium carbonate will produce carbon dioxide gas at a faster rate than the small marble chips, which in turn will produce carbon dioxide gas at a faster rate than the large marble chips. This can be observed from the steeper slope of the graph for powdered calcium carbonate compared to the slopes for small and large marble chips.Conclusion:The experimental evidence demonstrates that the surface area of a reactant affects the rate of reaction. As the surface area of the calcium carbonate increases, the rate of reaction with hydrochloric acid also increases. This is due to the increased number of collisions between reactant particles, leading to a higher probability of successful collisions and an increased rate of reaction.