To address the question of what effect cooling the system will have on the reaction between nitrogen gas (N₂) and oxygen gas (O₂), we need to consider the principles of equilibrium and thermodynamics, specifically Le Chatelier's principle.
### Reaction Considered
The reaction in question is:
[tex]\[ \text{Energy} + \text{N}_2(g) + \text{O}_2(g) \rightleftharpoons 2\text{NO}(g) \][/tex]
### Characteristics of the Reaction
From the provided reaction, it's clear that energy is a reactant. This means the reaction is endothermic, as it absorbs energy to form the products.
### Effect of Cooling
Cooling the system implies removing energy (heat) from the reaction environment.
- Le Chatelier's Principle: If a dynamic equilibrium is disturbed by changing the conditions, the position of equilibrium moves to counteract the change.
When we cool an endothermic reaction, we're effectively reducing the energy available for the forward reaction to proceed. According to Le Chatelier's principle, the equilibrium will shift to counteract this change by moving in the direction where energy (heat) is absorbed. For this specific reaction:
- Removing heat will shift the equilibrium toward the reactants to produce more energy.
- This shift means that the concentration of the reactants (N₂ and O₂) will increase, and the concentration of the product (NO) will decrease.
### Summary of Effects
Considering all the provided options:
1. It will add more NO(g) to the system.
- This is incorrect because cooling an endothermic reaction reduces the concentration of NO(g).
2. It will increase the concentration of N₂(g).
- This is correct because the equilibrium shifts to the left, increasing the amount of N₂(g).
3. It will decrease the rate of both the forward and the reverse reactions.
- The rates of reactions might change, but this option does not directly address the equilibrium shift.
4. It will shift the equilibrium to the right.
- This is incorrect because cooling an endothermic reaction shifts the equilibrium to the left (toward the reactants).
### Conclusion
Therefore, the most appropriate effect of cooling the system for this endothermic reaction is:
[tex]\[ \boxed{\text{It will increase the concentration of N}_2(g).} \][/tex]
