When pressure is increased in the equilibrium of the reaction 2SO2 + O2 ⇌ 2SO3, what is the effect?

In this reaction, 2 moles of sulfur dioxide (SO2) and 1 mole of oxygen (O2) combine to form 2 moles of sulfur trioxide (SO3). When considering the effect of pressure changes on an equilibrium system, Le Chatelier's principle is applied, which states that if a system at equilibrium is subjected to a change in conditions (like pressure), the system will respond by shifting the equilibrium position to counteract that change.

Increasing the pressure influences the system by favoring the direction that produces fewer moles of gas. In this case, the left side of the equilibrium has a total of 3 moles of gas (2 SO2 + 1 O2), while the right side has only 2 moles of gas (2 SO3). Therefore, when the pressure is increased, the equilibrium will shift towards the right, where there are fewer moles of gas present. This shift helps to reduce the pressure by favoring the production of SO3, where there are fewer gas molecules.

Thus, the statement that the equilibrium shifts to the right because of increased pressure is correct, as it reflects the system's natural response in order to relieve the stress applied by the pressure change.