Equilibrium Definition and 1000 Threads

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 that is 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, perfectly or almost perfectly balanced microscopic exchanges occur; this is the physical explanation of the notion of macroscopic equilibrium.
A thermodynamic system in a 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 systems that are at a state of non-equilibrium there are, by contrast, net flows of matter or energy. If such changes can be triggered to occur in a system in which they are not already occurring, the system is said to be in a meta-stable equilibrium.
Though 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.

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  1. P

    Finding the reaction force - moments and equilibrium

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  2. M

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  3. 3

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  4. A

    Need help with equilibrium equations - Please

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  5. S

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  6. M

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  7. B

    Nernst equation and equilibrium constant

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  8. S

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  9. S

    Unstable Equilibrium: Finding Critical Density of Low Density Beam in Water

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  10. Z

    Magnitude of force to keep stick in equilibrium.

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  11. E

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  12. A

    How Can I Solve for the Equilibrium Constants in These Equations?

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  13. A

    Archived The drift and diffusion currents under equilibrium

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  14. A

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  15. H

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  16. marellasunny

    Equilibrium reaction ICE method to ideal gas law

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  17. P

    L-J Potential-Distance of equilibrium

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  18. marellasunny

    Chemical equilibrium reaction for burned gases in engine

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  19. R

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  20. shounakbhatta

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  21. O

    Heat loss and thermal equilibrium of underground aquifer

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  22. G

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  23. R

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  24. Astrum

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  25. S

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  26. S

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  27. W

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  28. S

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  29. Y

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  30. H

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  31. M

    What is the relationship between particle velocity and sound waves in air?

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  32. J

    Find Amplitude and Equilibrium in Simple Harmonic Motion

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  33. M

    Simple harmonic motion/static equilibrium -spring problem, mass given

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  34. G

    Finding Equilibrium in a 3D System of Forces

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  35. N

    Finding the equilibrium points of a differential equation

  36. R

    Finding the distance between 2 charges in electric equilibrium.

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  37. H

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  38. M

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  39. S

    Torque and Equilibrium of a Rod

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  40. A

    How Do You Calculate Tension in a Hanging Mirror?

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  41. P

    Quick Static Equilibrium Questions

    Homework Statement A horizontal beam of weight W is supported by a hinge and cable as shown. The force exerted on the beam by the hinge has a vertical component that must be: Answer is nonzero and up. The pull P is just sufficient to keep the 14-N block and the weightless pulleys in...
  42. O

    Ideal gas-thermodynamics, thermal equilibrium

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  43. W

    Equilibrium bond lengths for excited molecules

    When making the Morse Potential graphs of diatomic molecules going through a transition, the excited state sometimes has a different equilibrium bond length. A visual example is here: http://en.wikipedia.org/wiki/File:Franck-Condon-diagram.png I was wondering how the average bond length of...
  44. L

    What Force is Needed to Wheel Over an Obstacle?

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  45. K

    Equilibrium - A rod influenced by multiple rope tensions

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  46. C

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  47. jaumzaum

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  48. H

    Equilibrium, Torque and Friction (hard)

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  49. T

    How Does Removing Ammonia Affect Chemical Equilibrium?

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  50. F

    Find equilibrium points given 2 differential equation

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