Final answer:
When the volume of the container is decreased, the equilibrium will shift to the right, favoring the production of more SO3.
Step-by-step explanation:
When the volume of the container is decreased, the pressure increases. According to Le Chatelier's principle, the equilibrium will shift in the direction that reduces the pressure. In this reaction, there are fewer moles of gas on the product side (2 moles of SO3) compared to the reactant side (3 moles of SO2 and 1 mole of O2). Therefore, the equilibrium will shift to the right, favoring the production of more SO3.