thermodynamic equilibrium

Thermodynamic equilibrium is an axiomatic concept of thermodynamics. It is an internal state of a single thermodynamic system, or a relation between several thermodynamic systems connected by more or less permeable or impermeable walls. In thermodynamic equilibrium there are no net macroscopic flows of matter or of energy, either within a system or between systems. In a system in its own state of internal thermodynamic equilibrium, no macroscopic change occurs. Systems in mutual thermodynamic equilibrium are simultaneously in mutual thermal, mechanical, chemical, and radiative equilibria. Systems can be in one kind of mutual equilibrium, though not in others. In thermodynamic equilibrium, all kinds of equilibrium hold at once and indefinitely, until disturbed by a thermodynamic operation. In a macroscopic equilibrium, almost or perfectly exactly balanced microscopic exchanges occur; this is the physical explanation of the notion of macroscopic equilibrium.

A thermodynamic system in its own state of internal thermodynamic equilibrium has a spatially uniform temperature. Its intensive properties, other than temperature, may be driven to spatial inhomogeneity by an unchanging long range force field imposed on it by its surroundings.

In non-equilibrium systems, by contrast, there are net flows of matter or energy. If such changes can be triggered to occur in a system in which they are not already occurring, it is said to be in a metastable equilibrium.

Though it is not a widely named law, it is an axiom of thermodynamics that there exist states of thermodynamic equilibrium. The second law of thermodynamics states that when a body of material starts from an equilibrium state, in which, portions of it are held at different states by more or less permeable or impermeable partitions, and a thermodynamic operation removes or makes the partitions more permeable and it is isolated, then it spontaneously reaches its own new state of internal thermodynamic equilibrium, and this is accompanied by an increase in the sum of the entropies of the portions. Wikipedia, Thermodynamic Equilibrium

See Also

center point balance equilibrium fulcrum
Chemical Equilibrium
differential equilibrium
disturbance of atomic equilibrium
Disturbance of Equilibrium
disturbance of negative equilibrium
disturbance of sympathetic equilibrium
electrically divided equilibrium
equative centre of equilibrium
equilibrium exchange
equilibrium level
equilibrium zone of pressure
Figure 13.14 - Equilibrium as Reciprocal Forces
Figure 13.15 - Equilibrium as Musical Tonal Equivalents
Figure 13.16 - Compound Equilibrium States
First Law of Thermodynamics
forces in equilibrium
harmony of equilibrium
Law of Compensation and Equilibrium
Laws of Thermodynamics
Neutral Equilibrium
resistant equilibrium
restoration of equilibrium
Russells Laws of Thermodynamics
Second Law of Thermodynamics
sympathetic disturbers of its equilibrium
sympathetic equilibrium
Third Law of Thermodynamics
transformation of equilibrium
universal equilibrium
universal equilibrium level
unstable equilibrium
zero of equilibrium
13.12 - Compound Equilibrium
13.12.1 - Disturbance of Equilibrium
8.32 - Electroacoustic Thermodynamic Transduction

Created by Dale Pond. Last Modification: Saturday November 24, 2018 06:45:43 MST by Dale Pond.