Question

What characteristics define a system at equilibrium.

Answer 1

Hint: We know the meaning of the word equilibrium. Equilibrium is a state of rest or balance due to the equal action of opposing forces. It is an equal balance between something. At equilibrium, the rate of forward reaction is equal to the rate of backward reaction.

Complete answer:
Equilibrium refers to the state of a system in which the concentration of the reactant and the concentration of the products do not change with time and the system does not display any further change in properties. The state of equilibrium is achieved by the system when the rate of forward reaction is equal to the rate of the reverse reaction. In homogeneous equilibrium, the reactants and products are all in the same phase.
While in heterogeneous equilibrium, the reactants and the products are in different phases. A stable equilibrium is the one in which when the body is displaced from its equilibrium state it tends to move towards that specific equilibrium point. For example, consider a ball that is kept at the bottom of a hemisphere. While in the case of the unstable equilibrium, when it is displaced from that specific point the body moves away from the point. A system is said to be in the stable state of equilibrium when it is displaced from equilibrium, it experiences the net force or the torque in such a direction that is opposite to the direction of the displacement. The two characteristics that define a system at equilibrium are:
The rates of forward and reverse reactions are equal.
All the reactants and products are present at equilibrium.
The Stability refers to the state of the rest of the body while the equilibrium is known as the state of the balance of a body. When a specific body is in the state of equilibrium, it stays in that particular position for as long as there is no external force or influence on it. This force tends to move it back towards its equilibrium position. Most of the systems are in stable equilibrium, especially in the case of the small displacements.

Note:
Remember that the system is said to be in dynamic equilibrium when there is no further change in the concentrations of the reactants and the products due to the equal rates of the forward and backward reactions. There are mainly two types of equilibrium. One is homogeneous equilibrium and another is heterogeneous equilibrium.