What happens to equilibrium if reactants are removed from the system?

When reactants are removed from a chemical system at equilibrium, the reaction responds according to Le Chatelier's principle. This principle states that if a system at equilibrium experiences a change in concentration, temperature, or pressure, the system will adjust to counteract that change and restore a new equilibrium.

In the scenario where reactants are removed, the concentration of the reactants decreases. To counteract this disturbance, the equilibrium will shift toward the side of the reaction that produces more reactants, which is typically referred to as shifting to the left in a classic forward reaction. This movement helps to partially restore the concentration of reactants, allowing the system to establish a new state of equilibrium.

Therefore, the correct answer is that the equilibrium shifts to the left, reflecting how the system adjusts to re-establish balance after the disturbance caused by the removal of reactants.