What is Equilibrium: Definition and 1000 Discussions

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. S

    Equilibrium ICE Table Question

    Homework Statement Keq at a given temperature is 4 2 HF (g) <--> H2 (g) + F2 (g) A 1 Litre jar contains 0.045 moles of fluorine at equilibrium. What was the initial quantity of hydrogen fluoride in the reaction jar? 2. The attempt at a solution I set the initial concentration...
  2. S

    Factors Affecting Equilibrium Questions.

    Homework Statement 1) Equilibrium is achieved in a closed system where metallic Mg can react with HCl(aq) according to the following net chemical equation: Mg(s) + 2 H+(aq) <--> Mg+2(aq)+ H2(aq) A sodium hydroxide, NaOH(s), pellet is added to this system. What happens to the concentration...
  3. E

    Calculate total energy from potential at equilibrium point

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  4. J

    Changing equilibrium point in damped simple harmonic motion

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  5. U

    Find the equilibrium position of this piston

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  6. Entanglement

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  7. Entanglement

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  8. A

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  9. M

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  10. M

    Thermal Equilibrium With Insulated Liquid And Gas Containers

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  11. M

    Visualizing Forces in equilibrium

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  12. S

    Can Aeration Change the Equilibrium of Gases in Water?

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  13. D

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  14. S

    A Question about Torque Used for Static Equilibrium

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  15. Entanglement

    Understanding Equilibrium Calculations: Debunking Misconceptions

    My solution for this question is Kc=1/10 As the ratio of both forward and backward rate constants never changes unless the temperature changes. My teacher told me that the answer is 1/100 because the reaction's products and reactants are doubled, that seems senseless to me, I don't want to...
  16. nicolauslamsiu

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  17. BrainMan

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  18. M

    Torque Equilibrium to find center of mass.

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  19. BrainMan

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  20. M

    Markov equilibrium probabilities

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  21. C

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  22. BrainMan

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  23. Y

    Decomposition of N2O5 Entropy Equilibrium

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  24. D

    Calculating pH of Buffered Solutions: Do You Need a Ka/Kb Value?

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  25. V

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  26. A

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  27. M

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  28. D

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  29. S

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  30. A

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  31. E

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  32. M

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  33. S

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  34. M

    What are the pin reactions at A and D?

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  35. Entanglement

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  36. L

    Hydrostatic Equilibrium in a Star

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  37. R

    Using Lagrange to solve rotating parabolic motion and equilibrium

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  38. Feodalherren

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  39. W

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  40. O

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  41. B

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  42. L

    Calculating equilibrium constant

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  43. S

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  44. A

    USAPhO 2014 F=ma exam #19, (tension, static equilibrium)

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  45. B

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  46. M

    Chemical Equilibrium of Reaction's constant?

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  47. P

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  48. D

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  49. M

    Thermal equilibrium for ice being added to liquid water

    Homework Statement 0.05625 m^3 of H2O(s) is added to a thermally isolated system of 20 L of H2O (l). If the ice was initially at 0 C and the liquid water was initially at 95 C, what is the final state and temperature? The Attempt at a Solution I missed class for this so I'm going by...
  50. greyshrop

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    I can't finish the last problems on my homework. I asked my teacher and he wouldn't help me, can someone please help me? I'm so confused!
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