<p>This work belongs to the field of chemical kinetics and is devoted to the frequency factor of particle collisions occurring in an inert gaseous or liquid medium. The objective of the research is to account for the influence of the inert medium on the rate of a chemical reaction. This was achieved using methods of traditional chemical kinetics and advanced mathematics (probability theory and mathematical analysis). By employing a special mathematical object – the Wiener sausage – an estimate of the probability of collision between two particles over time was obtained. In the case of multiple particles, the frequency factor was interpreted as a quantity proportional the collision probability. The new form of the Arrhenius equation derived in this study includes three terms on the pre-exponential factor, which adds novelty and significance to the research. Additionally, the paper provides a physical interpretation of each term in the newly obtained frequency factor formula and successfully validates the correctness of the new Arrhenius equation using a specific example for comparison with experimental results.</p>