Question

On increasing the pressure, in which direction will the gas phase reaction proceed to re-establish equilibrium, is predicted by applying the Le Chatelier’s principle. Consider the reaction: $N_2\left(g\right)+3H_2\left(g\right)\rightleftharpoons 2N{H}_3\left(g\right)$ .Which of the following is correct, if the total pressure at which the equilibrium is established, is increased without changing the temperature?

• A. $K$ will increase initially and decrease when pressure is very high.
• B. $K$ will increase
• C. $K$ will decrease
• D. $K$ will remain same

Answer 1

The correct option is D $K$ will remain same

$N_2\left(g\right)+3H_2\left(g\right)\rightleftharpoons 2N{H}_3\left(g\right)$

Since the pressure is increased, equilibrium will be shifted to the side where a smaller number of gaseous moles are present to compensate for the increase in pressure i.e., forward reaction. This is accordance with Le Chatelier’s principle.

Only when a change in temperature occurs, the value of equilibrium constant, $K$ will change.

As the temperature remains constant ,the value of $K$ does not change. Only the direction of reaction changes.

Therefore, the correct option is (A).