Standard 7g Preknowledge
7g) Students know the role a catalyst plays in increasing the reaction rate.
CALIFORNIA FRAMEWORKS SUMMARY: A catalyst increases the rate of a chemical reaction without taking part in the net reaction. A catalyst lowers the energy barrier between reactants and products by promoting a more favorable pathway for the reaction. Surfaces often play important roles as catalysts for many reactions. One reactant might be temporarily held on the surface of a catalyst. There the bonds of the reactant may be weakened, allowing another substance to react with it more quickly. Living systems speed up life-dependent reactions with biological catalysts called enzymes. Catalysts are used in automobile exhaust systems to reduce the emission of smog-producing unburned hydrocarbons.