For a heterogeneous catalytic reaction

• A. free energy of activation is lowered in the presence of catalyst, which remains unchanged at the end of reaction.
• B. a relatively small amount of catalyst can cause the conversion of large amount of reactants which does not mean that catalyst concentration is important.
• C. the catalyst does not form an intermediate complex with the reactant.
• D. the surface of the catalyst does not play an important role during reaction.