What is Equilibrium constant: Definition and 97 Discussions

The equilibrium constant of a chemical reaction is the value of its reaction quotient at chemical equilibrium, a state approached by a dynamic chemical system after sufficient time has elapsed at which its composition has no measurable tendency towards further change. For a given set of reaction conditions, the equilibrium constant is independent of the initial analytical concentrations of the reactant and product species in the mixture. Thus, given the initial composition of a system, known equilibrium constant values can be used to determine the composition of the system at equilibrium. However, reaction parameters like temperature, solvent, and ionic strength may all influence the value of the equilibrium constant.
A knowledge of equilibrium constants is essential for the understanding of many chemical systems, as well as biochemical processes such as oxygen transport by hemoglobin in blood and acid–base homeostasis in the human body.
Stability constants, formation constants, binding constants, association constants and dissociation constants are all types of equilibrium constants.

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  1. E

    I Equilibrium constant change with stoichiometric doubling (Callen)?

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  2. tbn032

    Chemistry Confusion in relation of Gibbs free energy and equilibrium constant

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  3. Huzaifa

    Chemistry Effect of temperature change in Le Chatelier's Principle

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  4. SilverSoldier

    Approximations in Chemical Equilibrium (add a weak acid HA into pure water)

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  5. I

    Calculate Equilibrium Constant for Polyprotic Acid Reaction

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  6. W

    Thermal Physics: Interpretation of equilibrium constant

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  7. M

    Kc = 1.88 for 2HI(g) ↔ H2(g) + I2(g)

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  8. harambe

    Equilibrium Constant for Alcohol and Acetic Acid Reaction at 25°C | Homework

    Homework Statement One mole of pure ethyl alcohol was treated with one mol of pure acetic acid at 25 °C.One third of acid changes into ester at equilibrium The equilibrium constant for the reaction will be Homework Equations C2H5OH+CH3COOH------>C2H5COOCH3[/B] K={A}^m{B}n/{C}^x{D}^z where...
  9. S

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  10. C

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  11. M

    MHB Calculate Equilibrium Constant of 2BrCl <=> Br2 + Cl2

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  12. U

    Pressure dependence of the equilibrium constant for an ideal gas

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  13. W

    Equilibrium constant Kp,eq issue

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  14. Aafia

    Calculate equilibrium constant?

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  15. Saracen Rue

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  16. E

    Trouble with Gibbs Free Energy & Equilibrium Constant Calc.

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  17. TheSodesa

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  18. Nader AbdlGhani

    What Does an Equilibrium Constant Value of 1 Mean and When is it Expected?

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  19. K

    Solving Dissociation Reaction Homework

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  20. G

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  21. N

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  22. G

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  23. MexChemE

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  24. patrickbotros

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  25. F

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  26. J

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  27. D

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  28. L

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  29. W

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  30. C

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  31. U

    Why is equilibrium constant K a product of the concentrations?

    So in a given amount of solution, the equilibrium constant is the product of the concentrations of the ionic species present, raised to the power of the stoichiometric coefficient. Wouldn't it make more sense if it was the sum of the concentrations though,since basically the net number of ions...
  32. B

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    The equation ΔG=-nFEcell, I understand. I also understand that, at unity activities of all species, Q=1 so R*T*ln(Q)=R*T*ln(1)=0. And therefore Ecell=E°cell and ΔG=ΔG°. However, surely we cannot then write that ΔG°=-nFE°cell=-R*T*ln(K), since ΔG° is measured at unity activity when Q=1, rather...
  33. A

    Equilibrium Constant Calculation

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  34. H

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  35. T

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  36. M

    Equilibrium constant vs rate constant - where kinetics meets thermodynamics?

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  37. M

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  38. S

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    Hello, I'm new to the forums and did in fact search for my thread before posting. I couldn't find anything that helped me with what I'm looking for. With that said, the problem I'm having is: 1) The value of Keq for the equilibrium H2+I2 → 2 HI is 794 at 25°C. What is the value of Keq for the...
  39. J

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    According to my teacher in my chemistry lesson, the equilibrium constant has different units depending on how many moles of reactant and product there are. But the idea of a constant which changes it's units depending on the situation seems a bit dodgy to me, especially as it seems to be related...
  40. H

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  41. M

    Equilibrium constant and concentration

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  42. M

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  43. Saladsamurai

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  44. W

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    Why are the concentrations of solids not incorporated into the equilibrium expression? All the books say it's because the "concentration of a pure solid is constant", but that doesn't make sense to me... If the solid is dissociating to produce a given product, why doesn't the concentration...
  45. M

    Equilibrium constant rules help.

    I was wondering where i could find a source for the rules to find Kc from a chemical formula? My professor tonight was changeing the formula like this: H2+Br2+2HBr then showed that 2H2+2Br2=4HBr...and getting different Kc values for each. I think that this is straight out wrong but she's the...
  46. A

    Calculate the equilibrium constant Kc for the reaction at this temperature

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  47. R

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  48. G

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  49. H

    Chemical Equilibrium Constant Calculation

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  50. A

    Equilibrium constant expression

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