Exercise 9 | Chemical Kinetics: Mechanisms

Calculate the ratio of the rate constants for a catalyzed and an uncatalyzed reaction at room temperature (25.0°C) if the activation energy is lowered by 10.0 kJ.mol-1 by the use of a catalyst.

Arrhenius equation:

k = Ae-Ea/RT

 

Ea (uncatalyzed reaction) = Ea (catalyzed reaction) + 10.0 kJ.mol-1

 

kcat / kuncat = Ae-Ea (cat)/RT / Ae-Ea (uncat)/RT

⇒ kcat / kuncat = e(- 1/RT (Ea(cat) – Ea(uncat))

⇒ kcat / kuncat = e10 × 1038.314 × 298 = 56.6