What are the characteristics of a system at equilibrium?

A system at equilibrium has a constant macroscopic property, no net change in concentration of reactants and products, and is reversible.

A system at equilibrium is a state where the forward and reverse reactions occur at the same rate, resulting in no net change in the concentration of the reactants and products. This means that although the reactions are still happening, the amounts of reactants and products remain constant over time because the rates of the forward and reverse reactions are equal.

One of the key characteristics of a system at equilibrium is that it is dynamic, not static. This means that the reactions are still ongoing, but they are happening at the same rate in both directions. Therefore, there is a constant exchange between reactants and products, but the overall concentrations do not change.

Another important characteristic is that a system at equilibrium is reversible. This means that the reaction can proceed in both the forward and reverse directions. The rate of the forward reaction equals the rate of the reverse reaction, maintaining a state of balance.

The equilibrium state is also dependent on the conditions of the system. Changes in temperature, pressure, or concentration can shift the equilibrium, altering the concentrations of the reactants and products. This is described by Le Chatelier's Principle, which states that if a dynamic equilibrium is disturbed by changing the conditions, the position of equilibrium shifts to counteract the change.

Lastly, a system at equilibrium exhibits constant macroscopic properties. This means that properties that can be observed on a large scale, such as colour, pressure, and density, remain constant when the system is at equilibrium. This is because these properties are directly related to the concentrations of the reactants and products, which, as mentioned earlier, do not change in a system at equilibrium.