Final answer:
Increasing the volume in the reaction vessel will cause the equilibrium to shift to the left, favoring the reactants.
Step-by-step explanation:
According to Le Chatelier's principle, if pressure is increased, then the equilibrium shifts to the side with the fewer number of moles of gas. In this reaction, there are three moles of gas on the reactant side and two moles of gas on the product side. Therefore, increasing the volume (which decreases the pressure) will cause the equilibrium to shift towards the side with more moles of gas, which is the reactant side. As a result, the equilibrium will shift to the left.