For an elementary chemical reaction, the Arrhenius plot is given below. [figure] If the energy of activation is 6.64 kJ mol-1 and R = 8.3 J K-1 mol-1, the temperature at which the rate constant becomes e2 min-1, is
- 250 K
- 125 K
- 150 K
- 200 K
Answer
(4) 200 K
Solution
From the Arrhenius equation:
k = A - EaRT
From the given plot of k vs 1/T, the intercept on the y-axis (at 1/T = 0) is A = 6.
When k = e2 min-1, k = 2.
Substituting the values:
2 = 6 - EaRT EaRT = 4
T = Ea4R = 6.64 103 J mol-14 8.3 J K-1 mol-1 = 664033.2 = 200 K
Answer: (4)