Changing the concentration of reactants in a chemical reaction at equilibrium will affect the rate of the reaction according to Le Chatelier's principle. Le Chatelier's principle states that if a system at equilibrium is subjected to a change in concentration, temperature, or pressure, the system will adjust itself to counteract the change and restore a new equilibrium.When the concentration of reactants is increased, the system will respond by shifting the equilibrium position to favor the formation of more products. This will increase the rate of the forward reaction, consuming the added reactants and forming more products until a new equilibrium is established. Conversely, if the concentration of reactants is decreased, the system will shift the equilibrium position to favor the formation of more reactants, increasing the rate of the reverse reaction and forming more reactants until a new equilibrium is reached.It is important to note that changing the concentration of reactants does not change the equilibrium constant K for the reaction, as it is only dependent on temperature. However, the reaction quotient Q will change, and the system will adjust to reach the equilibrium state where Q = K.