Question
Activation energy of a chemical reaction can be determined by
A.
evaluating rate constant at standard temperature
B.
evaluating velocities of reaction at two different temperatures
C.
evaluating rate constants at two different temperatures
D.
changing concentration of reactants
Answer :
evaluating rate constants at two different temperatures
Solution :
Activation energy can be calculated by using Arrhenius equation. The Arrhenius equation is
$$\log \frac{{{k_2}}}{{{k_1}}} = \frac{{{E_a}}}{{2.303R}}\left[ {\frac{{{T_2} - {T_1}}}{{{T_1}{T_2}}}} \right]$$
where, $${k_1}$$ and $${k_2} = $$ rate constants at two different temperatures, i.e. $$\,{T_1}$$ and $${T_2}$$ respectively.
$${E_a} = $$ Activation energy
$$R=$$ Gas constant
So, activation energy of a chemical reaction can be determined by evaluating rate constants at two different temperatures.