Question

The rate constants of a reaction at 500 K and 700 K are ${0.02s}^{-1}and0.07s^{-1}$ respectively. Calculate the values of Ea and A.

Answer 1

$log\frac{k_2}{k_1}$ = $\frac{E_a}{2.303\times R}(\frac{1}{T_1}-\frac{1}{T_2})$

Substituting the values,

$log\frac{0.07}{0.02}$ = $\frac{E_a}{2.303\times 8.314}(\frac{1}{500}-\frac{1}{700})$

$E_a=18.23kJ{mol}^{-1}$

$k=A\times e^{-E_a/RT}$

$0.02=A\times e^{-18230/8.314\times 500}$

$A=1.6s^{-1}$