Difference between revisions of "Bound energy"
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The ''free'' energy change (Helmoltz or Gibbs; ∆''A'' or ∆''G'') is the ''total'' energy change (total inner energy or enthalpy, ∆''U'' or ∆''H'') of a system minus the ''bound'' energy change. | The ''free'' energy change (Helmoltz or Gibbs; ∆''A'' or ∆''G'') is the ''total'' energy change (total inner energy or enthalpy, ∆''U'' or ∆''H'') of a system minus the ''bound'' energy change. | ||
Therefore, if a process occurs at [[equilibrium]], when ∆''G'' = 0, then ∆''H'' = ∆''B'', and at ∆<sub>e</sub>''W'' = 0 (∆''H'' = ∆<sub>e</sub>''Q'' + ∆<sub>e</sub>''W''; see [[energy]]) we obtain the definition of the bound energy as the heat change taking place in an equilibrium process (eq), | Therefore, if a process occurs at [[equilibrium]], when ∆''G'' = 0 (at constant gas pressure), then ∆''H'' = ∆''B'', and at ∆<sub>e</sub>''W'' = 0 (∆''H'' = ∆<sub>e</sub>''Q'' + ∆<sub>e</sub>''W''; see [[energy]]) we obtain the definition of the bound energy as the heat change taking place in an equilibrium process (eq), | ||
∆''B'' = ''T''∙∆''S'' = ∆<sub>e</sub>''Q''<sub>eq</sub> [Eq. 3] | ∆''B'' = ''T''∙∆''S'' = ∆<sub>e</sub>''Q''<sub>eq</sub> [Eq. 3] | ||
Revision as of 19:57, 29 December 2018
- high-resolution terminology - matching measurements at high-resolution
Bound energy
Description
The bound energy change in a closed system is that part of the energy change that is always bound to an exchange of heat,
∆B = ∆U - ∆A [Eq. 1]
∆B = ∆H - ∆G [Eq. 2]
The free energy change (Helmoltz or Gibbs; ∆A or ∆G) is the total energy change (total inner energy or enthalpy, ∆U or ∆H) of a system minus the bound energy change.
Therefore, if a process occurs at equilibrium, when ∆G = 0 (at constant gas pressure), then ∆H = ∆B, and at ∆eW = 0 (∆H = ∆eQ + ∆eW; see energy) we obtain the definition of the bound energy as the heat change taking place in an equilibrium process (eq),
∆B = T∙∆S = ∆eQeq [Eq. 3]
Abbreviation: B [J]
History
- From Kubo 1976 North-Holland: "Free energy" is due to H. van Helmholtz (1882), and means that part of the internal energy that can be converted into work, as seen in the equation dF = dA for an isothermal quasi-static process. It was customary to call the remaining part, TdS, of the internal energy, dU = dF+TdS, the gebundene Energie (bound energy), but this is not so common now.
- IUPAC: Helmholtz energy, A = U - TS [J]
- http://www.eoht.info/page/On+the+Thermodynamics+of+Chemical+Processes 2018-12-27
- Recalling the term bound energy helps to resolve one of the historic battles in thermodynamics [2].
References
- Kubo R (1976) Thermodynamics. An advanced course with problems and solutions. North-Holland Amsterdam, New York. -
- Gnaiger E (1994) Negative entropy for living systems: controversy between Nobel Laureates Schrödinger, Pauling and Perutz. In: What is Controlling Life? (Gnaiger E, Gellerich FN, Wyss M, eds) Modern Trends in BioThermoKinetics 3. Innsbruck Univ Press: 62-70. - »Bioblast link«
MitoPedia concepts:
Ergodynamics
