Questions: Le Chatelier: Adding Material or Energy The reaction shifts to the left (reactants). What happens to the amount of NO2 as the reaction shifts? 2 NO(g) + O2(g) ⇌ 2 NO2(g) + 113.06 kJ The amount of NO2 does not change. The amount of NO2 goes down. The amount of NO2 goes up.

Solution Steps

The given reaction is: \[ 2 \mathrm{NO}(\mathrm{~g})+\mathrm{O}_{2}(\mathrm{~g}) \rightleftharpoons 2 \mathrm{NO}_{2}(\mathrm{~g})+113.06 \mathrm{~kJ} \] This is an exothermic reaction, as indicated by the release of 113.06 kJ of energy.

Le Chatelier's Principle states that if a dynamic equilibrium is disturbed by changing the conditions, the position of equilibrium moves to counteract the change.

If the reaction shifts to the left, it means the equilibrium is moving towards the reactants. This shift can be caused by adding more products, removing reactants, or increasing the temperature (since the reaction is exothermic).

As the reaction shifts to the left, the amount of $\mathrm{NO}_{2}$ (a product) will decrease because the equilibrium is moving towards the reactants.

Final Answer