For the physical processes discussed above, following characteristics are common to the system at equilibrium:
- Equilibrium is possible only in a closed system at a given temperature.
- Both the opposing processes occur at the same rate and there is a dynamic but stable condition.
- All measurable properties of the system remain constant.
- When equilibrium is attained for a physical process, it is characterised by constant value of one of its parameters at a given temperature.
- The magnitude of such quantities at any stage indicates the extent to which the physical process has proceeded before reaching equilibrium.