What happens to equilibrium if the pressure of a gaseous system is increased?

When the pressure of a gaseous system at equilibrium is increased, the equilibrium will shift toward the side of the reaction that has fewer moles of gas. This is based on Le Chatelier's principle, which states that if an external change is applied to a system at equilibrium, the system will adjust to counteract that change.

In the case of increased pressure, the system will strive to reduce the pressure by favoring the side of the reaction with fewer gas moles. For example, if a reaction produces three moles of gas on one side and two moles on the other, an increase in pressure will encourage the reaction to shift to the side with two moles, thereby resulting in a net reduction in the overall gas volume and thus lowering the pressure again.

This behavior does not apply universally; in cases where both sides of the reaction have an equal number of gas moles, changes in pressure will not affect the position of equilibrium. However, the option stating that the equilibrium always shifts to the side with more moles would contradict the fundamental principle of achieving balance under increased pressure. Similarly, equilibrium does not shift randomly; it rather moves systematically under specific conditions to restore balance.