Review and Unit Quiz

Chemical kinetics is the study of factors that influence the rate at which chemical reactions occur. Chemical reactions are accelerated when conditions lead to an increase in the rate of molecular collisions that occur with sufficient energy to bring about a chemical change. This energy is specific to a particular reaction and is known as the activation energy, E_a. Increasing the temperature or concentration of reactants will increase the reaction rate, as will increasing the surface are of reactants. Chemical catalysts alter the rate at which a reaction occurs. They provide an alternate pathway that reduces the activation energy for a given reaction. Many reactions occur in a series of steps, or elementary reactions that produce transition states. A slow step that requires more energy than other steps will limit the rate at which a reaction can occur.