Question

Given the following reaction at equillibrium,
$N_2\left(g\right)+3H_2\left(g\right)\rightleftharpoons 2N{H}_3\left(g\right);\Delta H=-ve$
Some inert gas is added at constant pressure to the system. Predict which of the following facts will be affected?

• A. More $N{H}_3\left(g\right)$ is produced
• B. Less $N{H}_3\left(g\right)$ is produced
• C. No effect on equllibrium
• D. $K_p$ of the reaction is decreased

Answer 1

The correct option is B Less $N{H}_3\left(g\right)$ is produced

$N_2\left(g\right)+3H_2\left(g\right)\rightleftharpoons 2N{H}_3\left(g\right);\Delta H=-ve$
If an inert gas is added at a constant pressure, the reaction goes to that side where the number of moles increases. So reverse reaction takes place and less ammonia is produced.