Assertion : According to transition state theory, for the formation of an activated complex, one of the vibrational degrees of freedom is converted into a translational degree of freedom. Reason : Energy of the activated complex is higher than the energy of reactant molecules.

$: A+B \rightleftharpoons(A B)^{\#} \rightarrow$ products. The activated complex can also be treated as a distinct chemical species in equilibrium with the reactants which then decompose into products. It is, however, a special molecule in which one vibrational degree of freedom has been converted to a translational degree of freedom along the reaction coordinate. It must be remembered that the activated complex is not merely an intermediate in process of breaking or forming of chemical bonds. It is unstable because it is situated at the maximum of the potential energy barrier separating the produts from the reactants. The difference between the energy of the activated complex $\left(E_1\right)$ and the energy of the reactants $\left(E_2\right)$ is the activation energy, $E_a$. $$ E_1-E_2=E_a, E_1>>E_2 . $$