The energy of activation for a reaction is 100 kJ mo l - 1 . Presence of a catalyst lowers the activation energy by 75%. What will be effect on rate of reaction at 2 0 o C , other things being equal?

Step-by-step solution

The Arrhenius equation is k = A e - E a / RT In absence of catalyst, k 1 = A e - 100 / RT In presence of catalyst, k 2 = A e - 25 / RT So k 2 k 1 = e - 75 / RT or 2.303 lo g k 2 k 1 = 75 RT or 2.303 log k 2 k 1 = 75 8.314 × 1 0 - 3 × 293 or log k 2 k 1 = 75 8.314 × 1 0 - 3 × 293 × 2.303 or k 2 k 1 = 2.34 × 1 0 13 As the things being equal in presence or absence of a catalyst, k 2 = rate in presence of catalyst k 1 = rate in absence of catalyst i.e., r 2 r 1 = k 2 k 1 = 2.34 × 1 0 13