If we add more N2O4 to the reaction chamber, the equilibrium position will shift to the left, according to Le Chatelier's principle. This principle states that if a system at equilibrium is subjected to a change in concentration, temperature, or pressure, the system will adjust its equilibrium position to counteract the change.In this case, by adding more N2O4, the concentration of N2O4 increases. To counteract this change and re-establish equilibrium, the reaction will shift to the left, converting some of the added N2O4 into NO2. This shift will continue until a new equilibrium position is reached, where the rate of the forward reaction formation of N2O4 equals the rate of the reverse reaction formation of NO2 .