Changing the concentration of reactants in a chemical reaction can significantly affect the reaction rate and, in some cases, the reaction yield.1. Reaction rate: The reaction rate is the speed at which reactants are converted into products in a chemical reaction. According to the collision theory, the reaction rate is directly proportional to the frequency of effective collisions between reactant molecules. When the concentration of reactants is increased, there are more reactant molecules in the same volume, leading to a higher probability of effective collisions. As a result, the reaction rate increases.For many reactions, the reaction rate can be described by the rate law, which is an equation that relates the rate of a reaction to the concentrations of the reactants and a rate constant k . For example, for a reaction with reactants A and B, the rate law might be:Rate = k[A]^m[B]^nwhere m and n are the reaction orders with respect to A and B, respectively. In this case, increasing the concentration of either A or B will increase the reaction rate, depending on the values of m and n.2. Reaction yield: The reaction yield is the amount of product formed in a chemical reaction, usually expressed as a percentage of the theoretical maximum amount. The relationship between reactant concentration and reaction yield is more complex and depends on the specific reaction and its mechanism.In some cases, increasing the concentration of reactants can lead to a higher reaction yield, especially if the reaction is reversible and the equilibrium shifts towards the product side. However, in other cases, increasing the concentration of reactants may not affect the reaction yield significantly, or it may even lead to a lower yield if side reactions become more prominent at higher concentrations.In summary, changing the concentration of reactants can affect the reaction rate by increasing the frequency of effective collisions between reactant molecules, leading to a faster reaction. The effect on reaction yield depends on the specific reaction and its mechanism, with the potential for increased, unchanged, or decreased yields.