Definition - What does Thermodynamic Equilibrium mean?
Thermodynamic equilibrium is a state that is achieved when a system satisfies three types of equilibriums, i.e., thermal equilibrium, chemical equilibrium and mechanical equilibrium. Thermodynamic equilibrium condition of a system is explained by the Zeroth law of thermodynamics. As per this law of thermodynamics, if the first object is in equilibrium with the second object and the second object is in equilibrium with the third object, then first and third objects will also be in equilibrium. Thus, the objects in the thermodynamic equilibrium will have the same temperature.
Petropedia explains Thermodynamic Equilibrium
A thermodynamic system which is in a state of internal thermodynamic equilibrium has a uniform temperature. Thermodynamic equilibrium state involves the satisfaction of thermal, chemical and mechanical equilibriums by a system.
- Thermal Equilibrium is a state at which two substances in physical contact have no difference in their body temperatures, i.e., either the objects have same temperature or both objects are connected by a permeable barrier that does not allow the transfer of heat between the two objects. Thermal equilibrium is mainly associated with the laws of thermodynamics in physics and mechanics.
- Chemical Equilibrium is a state whereby there is no chemical reaction taking place between the various objects, or any transfer of matter from one part of the system to another part because of any kind of diffusion. Thus, during chemical equilibrium, the chemical potential of various systems remains the same.
- Mechanical Equilibrium is a state whereby there are no unbalanced forces acting within the system or between the system and its surroundings. Thus, the pressure throughout the system remains the same or constant.