Consider the reaction N2 (g) + 3 H2 (g) 2 NH3 (g), which is exothermic as written. What would be the effect on the equilibrium position of adding N2 (g) ?

Shift to the right side

Explanation:

Remember that any stress that we bring to a chemical equilibrium, will be answered by this in such a way as to minimize the disturbance and attain equilibrium again. This is known as LeChatelier's principle.

If we add N₂ (g) to the system at equilibrium

N₂ (g) + 3 H₂ (g) ⇄ 2 NH₃ (g)

the equilibrium will consume part of the added N₂ gas until it reaches equilibrium again producing more ammonia (NH₃).

Mathematically this is equivalent to a decrease the pressure of N₂ so that the equilibrium partial pressures of the gases obey the equilbrium pressure constant Kp.

Therefore the equilibrium will shift to the product side.