Adding a catalyst to a reaction system does not change the equilibrium position of the reaction. A catalyst works by lowering the activation energy of a reaction, which increases the rate at which the reaction proceeds. This means that both the forward and reverse reactions are sped up equally, allowing the system to reach equilibrium faster. However, the equilibrium constant K and the equilibrium concentrations of the reactants and products remain unchanged.Le Chatelier's principle states that if a change is applied to a system at equilibrium, the system will adjust itself to counteract the change and restore a new equilibrium. Since a catalyst does not change the equilibrium constant or concentrations, it does not affect the position of the equilibrium according to Le Chatelier's principle.It is important to note that a catalyst cannot be used to shift the equilibrium position of a reaction. The equilibrium position can only be changed by altering the concentrations of the reactants or products, changing the temperature, or changing the pressure for reactions involving gases . A catalyst merely helps the reaction reach equilibrium faster.An example of a reaction where a catalyst is used to speed up the reaction, but not to shift the equilibrium position, is the decomposition of hydrogen peroxide H2O2 into water H2O and oxygen gas O2 :2 H2O2 aq 2 H2O l + O2 g In this reaction, a catalyst such as manganese dioxide MnO2 can be added to increase the rate of decomposition, but it does not change the equilibrium position of the reaction. The system will still reach the same equilibrium concentrations of hydrogen peroxide, water, and oxygen gas, but it will do so more quickly with the catalyst present.