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Role of Catalysts . Homogenous vs. Heterogeneous Catalysts Determining E a for catalyzed reactions. What is a catalyst?. Substance that speeds up rxn without being consumed . How does it work?. Provides new pathway with a lower E a Creates new mechanism
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Role of Catalysts Homogenous vs. Heterogeneous Catalysts Determining Ea for catalyzed reactions
What is a catalyst? • Substance that speeds up rxn without being consumed How does it work? • Provides new pathway with a lower Ea • Creates new mechanism • Fraction of collisions more effective • Reaction Rate Increases
DOES NOT change overall ΔE (R P) • DOES change Ea
Homogeneous Catalyst • Present in same phase as the reactant molecules
Heterogeneous Catalyst • Usually gases being adsorbed on solid surface • present in a different phase as reactants Example: Hydrogenation