According to Le Chatelier's principle, what happens when more product is added to an equilibrium mixture?

• A. System shifts to consume added product, toward reactants.
• B. System shifts toward additional product formation.
• C. The equilibrium constant decreases.
• D. Temperature rises spontaneously.

Answer: (A)

Le Chatelier's principle says a system at equilibrium shifts to counteract a disturbance. When extra product is added, its concentration rises and the system responds by favoring the reverse reaction, which consumes product and makes more reactant. In other words, the equilibrium shifts toward the reactants to reduce the excess product and restore balance. The equilibrium constant remains unchanged at a given temperature, so this shift is about rebalancing concentrations rather than changing K.