Diffusion-limited reactions

Diffusion-limited reactions occur when the rate at which molecules react depends primarily on how quickly they can move and find each other through diffusion. In these processes, the reactants are so mobile that their encounter rate is the limiting factor; once they meet, they react almost immediately. This process is common in biological systems and certain chemical reactions where the transportation of molecules is slow relative to their reaction speed. Therefore, the overall reaction rate is determined mainly by diffusion, not by the actual chemical transformation once the molecules meet.