Which of the following statements about a chemical system in equilibrium is correct/ The
Answer Details
The correct statement about a chemical system in equilibrium is that "equilibrium is re-established when a stress is applied."
Chemical equilibrium is a state where the forward and backward reactions occur at equal rates, resulting in no net change in the concentration of reactants or products. It is a dynamic state where the system appears to be static because the rates of forward and backward reactions are equal.
However, a system in equilibrium is not unchangeable and can be disturbed by changes in concentration, pressure, or temperature. Such changes are referred to as "stresses." When a stress is applied to an equilibrium system, the system responds by shifting the equilibrium position in a direction that reduces the stress. This means that the concentration of the reactants and products will change until a new equilibrium is established.
Therefore, the only correct option is that "equilibrium is re-established when a stress is applied." The other options are incorrect because a system in equilibrium is reversible, and the reaction may not go to completion. Additionally, the equilibrium position is not affected by a catalyst because it only speeds up the rate of the reaction without affecting the position of equilibrium.