In free radical polymerization, the molecular weight of the synthesized polymer is influenced by the concentration of the monomer. The relationship between monomer concentration and molecular weight can be understood by considering the kinetics of the polymerization process.During free radical polymerization, the process consists of three main steps: initiation, propagation, and termination. The initiation step involves the formation of free radicals, which then react with monomers to form active polymer chains. The propagation step involves the continuous addition of monomers to the growing polymer chains. Termination occurs when two active polymer chains react with each other, or when an active chain reacts with a radical scavenger, effectively ending the growth of the polymer chain.The molecular weight of the polymer is mainly determined by the rate of termination. In general, as the monomer concentration increases, the rate of termination decreases. This is because the higher concentration of monomers leads to a higher rate of propagation, which in turn reduces the probability of two active polymer chains encountering each other and terminating.As a result, when the monomer concentration is increased, the average molecular weight of the synthesized polymer also increases. This is because the polymer chains have more opportunities to grow longer before termination occurs.However, it is important to note that other factors, such as temperature, initiator concentration, and reaction conditions, can also influence the molecular weight of the polymer. Therefore, while increasing monomer concentration generally leads to an increase in molecular weight, it is essential to consider the overall reaction system to optimize the desired polymer properties.