Question

Question: Ammonia is produced by the Haber process, in which nitrogen and hydrogen are reacted directly using an iron mesh impregnated with oxides as a catalyst. For the reaction

${\mathbf{\text{N}}}_{\mathbf{2}}\left(g\right)\mathbf{+}\mathbf{3}{\mathbf{H}}_{\mathbf{2}}\left(g\right)\mathbf{\to }\mathbf{}\mathbf{2}{\mathbf{NH}}_{\mathbf{3}}\left(g\right)$

equilibrium constants as a function of temperature are

300^oC, 4.34×10^-3

500^oC, 1.45×10^-5

600^oC, 2.25×10^-6

Is the reaction exothermic or endothermic? Explain.

Short answer

The given reaction is exothermic.

Step-by-step solution

 Step1: Find whether the given reaction is exothermic or endothermic.

The equilibrium constant, K, is directly proportional to the temperature in an endothermic reaction.For endothermic reactions, the equilibrium constant increases with increasing the temperature.This is not agreed with an endothermic reaction.

Is the given reaction exothermic or not?

In the case of an exothermic reaction, the equilibrium constant, K, is inversely proportional to the temperature.For exothermic reactions, the equilibrium constant decreases with increasing the temperature.This is valid with an endothermic reaction.

Hence, the given reaction is exothermic.