question_answer 40)

  The role of a catalyst is to change.......... (a) Gibbs energy of reaction            (b) enthalpy of reaction (c) activation energy of reaction        (d) equilibrium constant

Answer:

                (c) The role of a catalyst is to change the activation energy of reaction. This is done by either increasing or decreasing activation energy of molecule as catalyst are mainly of two types; +ve catalyst and -ve catalyst. Note Catalyst are of two types one is positive catalyst which increases rate of reaction by decreasing activation energy and another is negative catalyst which decreases rate of reaction by increasing energy of activation.