In the absence of a catalyst

CHEMISTRY · Single correct · A Level · Chemistry · Kinetics · Kinetics

Problem

In the absence of a catalyst, a first-order decomposition has a rate constant of

1.2 \times 10^{-5}\,\text{s}^{-1}

25\,^{\circ}\text{C}

and an activation energy of

95\,\text{kJ}\cdot\text{mol}^{-1}

. A catalyst provides an alternative two-step pathway that lowers the overall activation energy by

45\,\text{kJ}\cdot\text{mol}^{-1}

while leaving the pre-exponential factor unchanged. Which of the following is closest to the new rate constant at

25\,^{\circ}\text{C}

? (a)

7 \times 10^{3}\,\text{s}^{-1}

(b)

2 \times 10^{2}\,\text{s}^{-1}

(c)

9 \times 10^{2}\,\text{s}^{-1}

(d)

5 \times 10^{4}\,\text{s}^{-1}