Elementary gas-phase reactions of the bimolecular type A + B -> Products are characterized by the second order kinetic law -d[A]/dt=k[A][B], where [A] and [B] are the concentrations of A and B species, t is time and k is the rate constant, usually es
timated by means of Eyring equation. Here, we show that its standard derivation, as such, is not consistent with the second order law. This contradiction is however removed by introducing a correlation between what we call potentially reactive pairs. A new derivation of Eyring equation is finally proposed on the basis of the previous findings.
