Question

In the formation of nitric oxide, $~{{N}_{2}}$ and ${{O}_{2}}$ are made to combine. Which of the following conditions will favor the formation of NO?
\[{{N}_{2}}+{{O}_{2}}\rightleftharpoons 2NO+Heat\]
A. Low temperature
B. High Temperature
C. Freezing point
D. All are favorable

Answer 1

Hint: Le-Chatelier's principle will explain which reaction conditions (pressure, Temperature and concentration) are favorable for the formation of the products in high yield. By changing the reaction conditions the reaction the equilibrium of the chemical reaction shifts either towards reactant side or product side.

Complete Solution :
- In the given question it is given that which reaction conditions favors the formation of nitric oxide.
- The given chemical reaction is as follows.
\[{{N}_{2}}+{{O}_{2}}\rightleftharpoons 2NO+Heat\]
- In the above chemical reaction one mole of nitrogen reacts with one mole of oxygen and forms two moles of nitric oxide and liberates huge amounts of heat.
- Means the formation of nitric oxide by the reaction of nitrogen and oxygen is an exothermic reaction (heat liberates).
- As per the Le-Chatelier's principle to shift the equilibrium of the exothermic reaction towards the products side we should decrease or lower the temperature of the reaction.
- By decreasing the temperature of the exothermic reaction we can get a huge amount of the product.
- Therefore to get the maximum amount of the formation of NO in the given reaction we should lower the temperature of the reaction.
So, the correct answer is “Option A”.

Note: If we increase the temperature of the exothermic reaction the equilibrium of the reaction shifts towards the left side (towards the formation of the reactants) then we are not supposed to increase the temperature of the exothermic reaction.