Question

The favorable conditions for the reaction ${{N}_{2}}+{{O}_{2}}\leftrightarrows 2NO+heat$ is
a.) Increase in concentration of reactants
b.) Increase in pressure
c.) Decrease in temperature
d.) None of the above

Answer 1

Hint: In a reversible reaction, equilibrium is established. For an exothermic reaction, removal of heat moves the reaction in a forward direction. Increase in concentration of reactant also shifts equilibrium from left to right.

Complete step by step answer:
-This reaction is a reversible reaction. Equilibrium is established between molecular nitrogen, molecular oxygen and NO.
- Le chatelier principle can be applied which states, when any stress is applied on a system, the system will adjust itself in such a way that the effect of stress is reduced or nullified.
-As formation of NO is an exothermic reaction as heat is liberated. By decreasing the temperature of reaction, removal of heat shift equilibrium from left to right and yield of NO can be increased.
- ${{N}_{2}}+{{O}_{2}} \leftrightarrows 2NO+heat$

-Also, increase in concentration of reactants will lead to increase in yield of product because more of reactant will react to form product and reestablish equilibrium.
-increase or decrease in pressure will have no effect on equilibrium as the number of moles of reactant and product are equal.
Hence, the favorable conditions for the reaction ${{N}_{2}}+{{O}_{2}} \leftrightarrows 2NO+heat$ are So, the correct answer is “Option A and C”.

Note: To increase the yield of products, the change should be such that the reaction occurs in a forward direction. Increase in concentration of reactants or decrease in concentration of product leads to forward direction. For an exothermic reaction, removal of heat leads to forward reaction and for an endothermic reaction, addition of heat leads to forward reaction