Reaction rates

This document discusses factors that affect the rate of chemical reactions. It identifies six main factors: concentration, size of reactants, surface area, pressure, temperature, and presence of a catalyst. It provides examples for how increasing each factor, such as increasing the concentration of reactants or dividing reactants into smaller pieces, can increase the rate of reactions through more frequent collisions between molecules. Catalysts are specifically noted as substances that increase reaction rates without being used up in the reactions.