Reaction rates. In a solid-liquid reaction, reaction rate increases with the surface area of the solid. This effect is demonstrated here using the reaction of chalk (calcium carbonate, CaCO3) with 0.2M hydrochloric acid (HCl). Carbon dioxide (CO2) bubbles are produced: CaCO3 + HCl -> CaCl2 + H2O + CO2. The left beaker has a single piece of chalk, while in the right beaker has the same amount of chalk, but broken down into many smaller pieces, increasing the surface area. The reaction is visibly more vigorous (higher reaction rate) in the right beaker.
Model release not required. Property release not required.