University of Central Florida (UCF) CHM2046 Chemistry Fundamentals II Test 3 Practice Test

When the volume of a system at equilibrium is increased, the equilibrium will shift to the side with more moles of gas. This shift occurs to counteract the change introduced by the increase in volume, as described by Le Chatelier's principle.

In the context of gas reactions, when the volume increases, the pressure decreases. The equilibrium will adjust itself in such a way as to increase the pressure again. Since gases occupy space and contribute to pressure, the side of the reaction that has a greater number of moles of gas will be favored. This shift toward the side with more moles of gas results in an increase in the concentration of gaseous reactants or products, helping to restore the pressure balance.

This principle is crucial for understanding how various factors affecting a chemical equilibrium, including changes in volume, influence the direction of the reaction.