Difference between revisions of "Bound energy"
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|abbr=''B'' [J] | |abbr=''B'' [J] | ||
|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]], | |description=The '''bound energy''' change in a closed system is that part of the ''total'' [[energy]] change that is always bound to an exchange of [[heat]], | ||
ย | ย d''B'' = d''U'' - d''A'' [Eq. 1] | ||
ย โ''B'' = โ''H'' - โ''G'' [Eq. 2] | ย โ''B'' = โ''H'' - โ''G'' [Eq. 2] | ||
The ''free'' energy change (Helmoltz or Gibbs; | The ''free'' energy change (Helmoltz or Gibbs; d''A'' or d''G'') is the ''total'' energy change (total inner energy or enthalpy, d''U'' or d''H'') of a system minus the ''bound'' energy change. | ||
Therefore, if a process occurs at [[equilibrium]], when | Therefore, if a process occurs at [[equilibrium]], when d''G'' = 0 (at constant gas pressure), then d''H'' = d''B'', and at d<sub>e</sub>''W'' = 0 (d''H'' = d<sub>e</sub>''Q'' + d<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), | ||
ย | ย d''B'' = ''T''โd''S'' = d<sub>e</sub>''Q''<sub>eq</sub> [Eq. 3] | ||
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::::::* IUPAC: Helmholtz energy, ''A'' = ''U'' - ''TS'' [J] | ::::::* IUPAC: Helmholtz energy, ''A'' = ''U'' - ''TS'' [J] | ||
::::::* http://www.eoht.info/page/On+the+Thermodynamics+of+Chemical+Processes 2018-12-27 ย | ::::::* http://www.eoht.info/page/On+the+Thermodynamics+of+Chemical+Processes 2018-12-27 ย | ||
::::* | ::::* The term ''bound energy'' helps to resolve one of the historic battles in thermodynamics [2]. ย | ||
== References == | == References == |
Latest revision as of 15:05, 31 December 2018
Description
The bound energy change in a closed system is that part of the total energy change that is always bound to an exchange of heat,
dB = dU - dA [Eq. 1]
โB = โH - โG [Eq. 2]
The free energy change (Helmoltz or Gibbs; dA or dG) is the total energy change (total inner energy or enthalpy, dU or dH) of a system minus the bound energy change.
Therefore, if a process occurs at equilibrium, when dG = 0 (at constant gas pressure), then dH = dB, and at deW = 0 (dH = deQ + deW; see energy) we obtain the definition of the bound energy as the heat change taking place in an equilibrium process (eq),
dB = TโdS = deQeq [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
- 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 Schrรถdinger, 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. - ยปBioblast linkยซ
MitoPedia concepts:
Ergodynamics