Question

Here's a question for the chemistry student to solve based on the subtopic of predicting the direction of a reaction at equilibrium:If the concentration of nitrogen dioxide (NO2) gas in a sealed container at equilibrium at a temperature of 450 K is increased, what will be the effect on the concentration of nitrogen monoxide (NO) in the container?

Answer 1

To answer this question, we first need to know the balanced chemical equation for the reaction between nitrogen dioxide  NO2  and nitrogen monoxide  NO . The reaction is as follows:2 NO2  N2O4This reaction is reversible, and it reaches equilibrium when the rate of the forward reaction equals the rate of the reverse reaction. According to Le Chatelier's principle, if a change is made to a system at equilibrium, the system will adjust itself to counteract that change and restore equilibrium.In this case, the concentration of NO2 is increased. According to Le Chatelier's principle, the system will try to counteract this change by shifting the equilibrium position to consume the excess NO2. The reaction will shift to the right  forward direction , producing more N2O4.As the reaction shifts to the right, it will consume NO2 and produce N2O4. Since NO is not directly involved in this reaction, its concentration will not be affected by the increase in NO2 concentration. Therefore, the concentration of nitrogen monoxide  NO  in the container will remain unchanged.