Activation energy of a chemical reaction can be determined by

Solution :
We know that the activation energy of chemical reaction is given by formula
$$\frac{{{k_2}}}{{{k_1}}} = \frac{{{E_a}}}{{2.303R}}\left[ {\frac{{{T_2} - {T_1}}}{{{T_1}{T_2}}}} \right],$$       where $${{k_1}}$$  is the rate constant at temperature $${T_1}$$  and $${k_2}$$  is the rate constant at temperature $${T_2}$$  and $${E_a}$$ is the activation energy. Therefore activation energy of chemical reaction is determined by evaluating rate constant at two different temperatures.