Changing the concentration of reactants affects the rate of a chemical reaction because it influences the frequency of collisions between reactant molecules. In general, increasing the concentration of reactants leads to an increase in the rate of reaction, as there are more molecules available to collide and react with each other. Conversely, decreasing the concentration of reactants results in a slower reaction rate due to fewer collisions between molecules.This relationship between concentration and reaction rate can be modeled mathematically using the rate law equation:rate = k[A]^m[B]^nIn this equation:- rate represents the rate of the reaction- k is the rate constant, which is specific to the reaction and depends on factors like temperature and the presence of catalysts- [A] and [B] are the concentrations of the reactants A and B, respectively- m and n are the reaction orders with respect to reactants A and B, respectivelyThe reaction orders m and n indicate how the rate of the reaction is affected by changes in the concentration of each reactant. For example, if m = 1, the reaction is first-order with respect to reactant A, meaning that the rate of the reaction is directly proportional to the concentration of A. If m = 2, the reaction is second-order with respect to A, meaning that the rate of the reaction is proportional to the square of the concentration of A. The overall order of the reaction is the sum of the individual orders m + n .It's important to note that the reaction orders and the rate constant must be determined experimentally, as they cannot be predicted from the balanced chemical equation alone. Once these values are known, the rate law equation can be used to predict how changes in reactant concentrations will affect the rate of the reaction.