# Exercise 5 | Chemical Kinetics: Mechanisms

The rate of an elementary reaction has been studied as a function of temperature.

The following data were obtained for the rate constant:

Exp 1: T = 300K; k = 6.47 mol.L-1.s-1

Exp 2: T = 500K; k = 2.84 x 104 mol.L-1.s-1

Exp 3: T = 700K; k = 1.03 x 106 mol.L-1.s-1

Calculate the activation energy for the reaction.

Arrhenius equation:

k = Ae-Ea/RT

k2 / k1 = Ae-Ea/RT2 / Ae-Ea/RT1

k2 / k1 = e-Ea/RT2 + Ea/RT1

ln (k2 / k1) = $\frac{{\mathrm{E}}_{\mathrm{a}}}{\mathrm{R}}$

⇒ Ea =  = 5.23 x 104 J = 52.3 kJ