Le Chatelier's Principle; Pressure

Question

Given the following reaction:

3 H₂(g) + N₂(g) <--> 2NH₃(g)

If the pressure of the reaction is decreased, the reaction will shift to the ___ to restore equilibrium.

A. Left

B. Right

Answer 1

If the pressure is DECREASED, the reaction will shift to the left (answer A). The reason is because there are 4 moles of reactants and 2 moles of products (all gases), so decreasing the pressure will affect the left side (reactant side) more and the shift will be in that direction in an attempt to restore the equilibrium.