Adding NO₂ to the equilibrium reaction 3NO(g) → N₂O(g) + NO₂(g) will cause the reaction to shift left, leading to the production of more NO as a response to the change in the system.
When NO₂ is added to the system with the reaction 3NO(g) → N₂O(g) + NO₂(g), the system will shift to the left, meaning more NO will form. This shift is explained by Le Chatelier's Principle, which states that if a stress is applied to a system at equilibrium, the system shifts in the direction that tends to reduce the stress. In this case, adding more NO₂ increases the concentration of one of the products, so to reduce this stress, the reaction will shift towards the reactants, increasing the production of NO.
If we consider a different reaction, such as N₂(g) + O₂(g) = 2NO(g), and O₂ is added, according to Le Chatelier's Principle, the equilibrium will shift to the right to reduce the concentration of the added O₂, thereby producing more NO.
When NO₂ is added to the system in the given reaction, it will shift the equilibrium to the left, favoring the formation of more reactants. In this case, more NO will form as the reaction is driven towards the reactant side. This is because the formation of additional NO₂ decreases the total number of molecules in the system, reducing the total pressure and relieving the stress.