Question

In the reaction ${\mathrm{N}}_2+{\mathrm{O}}_2\to 2\mathrm{NO}-\mathrm{Heat}$ which of the following conditions is suitable to get a good yield of $\mathrm{NO}$?

• A. Increase in temperature
• B. Decrease in temperature
• C. Increase in pressure
• D. The addition of a catalyst

Answer 1

The correct option is A

Increase in temperature

The explanation for the correct option: (A)

1. The chemical reactions which proceed with the absorption of heat energy are called endothermic reactions.
2. The given reaction is endothermic in the forward direction.
3. According to Le-Chatelier’s principle, if any change is made to equilibrium then the position of equilibrium shifts in order to counteract that change to re-establish the equilibrium.
4. Therefore, an increase in temperature favours the formation of $\mathrm{NO}$.

The explanation for the incorrect options:

(B) Decrease in temperature is not a suitable condition to get a good yield of $\mathrm{NO}$.

(C) Increase in pressure is not a suitable condition to get a good yield of $\mathrm{NO}$.

(D) The addition of a catalyst is not a suitable condition to get a good yield of $\mathrm{NO}$ as it only alters the rate of reaction.

Conclusion: Hence option (a) is correct.