Reaction rates. Reaction rate increases with concentration of reactants. This effect is demonstrated here using the reaction of chalk (calcium carbonate, CaCO3) with hydrochloric acid (HCl). Carbon dioxide (CO2) bubbles are produced: CaCO3 + HCl -> CaCl2 + H2O + CO2. In the left beaker the concentration of hydrochloric acid is 0.5M, while in the right beaker the concentration is 0.2M. The reaction is visibly more vigorous (higher reaction rate) in the left beaker.
Model release not required. Property release not required.