Advancement per volume: Difference between revisions
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|abbr=d<sub>tr</sub>''Y'' | |abbr=d<sub>tr</sub>''Y'' | ||
|description=''' | |description='''Advancement per volume''' or volume-specific advancement, d<sub>tr</sub>''Y'' [molβ''V''<sup>-1</sup>], is related to [[advancement]], d<sub>tr</sub>''Y'' = d<sub>tr</sub>''ΞΎ''βV<sup>-1</sup>, as is the amount of substance per volume, ''c''<sub>i</sub> ([[concentration]]) [molβ''V''<sup>-1</sup>], related to [[amount]], ''c''<sub>''i''</sub> = = ''n''<sub>i</sub>β''V''<sup>-1</sup>. Advancement per volume is particularly introduced for chemical reactions, d<sub>r</sub>''Y'', where it has the dimension of a concentration. In an [[open system]] at steady-state, however, the concentration does not change as the reaction advances. Only in [[closed system]]s, specific advancement is the change in concentration divided by the stoichiometric number, Ξ<sub>r</sub>''Y'' = Ξ''c<sub>i</sub>''/''Ξ½<sub>i</sub>''. In general, Ξ''c<sub>i</sub>'' is replaced by the partial change of concentration, Ξ<sub>r</sub>''c<sub>i</sub>'', which contributes to the total change of concentration, Ξ''c<sub>i</sub>''. In open systems at steady-state, Ξ<sub>r</sub>''c<sub>i</sub>'' is compensated by external processes, Ξ<sub>ext</sub>''c<sub>i</sub>'', exerting an effect on the total concentration change, Ξ''c<sub>i</sub>'' = Ξ<sub>r</sub>''c<sub>i</sub>'' + Ξ<sub>ext</sub>''c<sub>i</sub>'' = 0.Β Β | ||
|info=[[Gnaiger_1993_Pure Appl Chem]] | |info=[[Gnaiger_1993_Pure Appl Chem]] | ||
}} | }} | ||
== Application in respirometry == | |||
:::: In typical liquid phase reactions the volume of the system does not change during the reaction. When oxygen consumption (''Ξ½''<sub>O2</sub> = -1 in the chemical reaction) is measured in aqueous solution, then the volume-specific [[oxygen flux]] is the time derivative of the advancement of the reaction per volume [1], ''J''<sub>''V'',O2</sub> = d<sub>r</sub>''Y''<sub>O2</sub>/d''t'' = d<sub>r</sub>''ΞΎ''<sub>O2</sub>/d''t''β''V''<sup>-1</sup> [(molβsΒ<sup>-1</sup>)βLΒ<sup>-1</sup>]. The rate of O<sub>2</sub> concentration change is d''c''<sub>O2</sub>/d''t'' [(molβLΒ<sup>-1</sup>)βsΒ<sup>-1</sup>], where concentration is ''c''<sub>O2</sub> = ''n''<sub>O2</sub>β''V''<sup>-1</sup>. There is a difference between (''1'') ''J''<sub>''V'',O2</sub> [molβsΒ<sup>-1</sup>βLΒ<sup>-1</sup>] and (''2'') rate of concentration change [molβLΒ<sup>-1</sup>βsΒ<sup>-1</sup>]. These merge to a single expression only in a closed system. In open systems, internal transformations (catabolic flux, O<sub>2</sub> consumption) are distinguished from external flux (such as O<sub>2</sub> supply). External fluxes of all substances are zero in closed systems [2]. | |||
{{MitoPedia concepts | {{MitoPedia concepts | ||
|mitopedia concept=Ergodynamics | |mitopedia concept=Ergodynamics | ||
}} | }} |
Revision as of 21:00, 19 October 2018
Description
Advancement per volume or volume-specific advancement, dtrY [molβV-1], is related to advancement, dtrY = dtrΞΎβV-1, as is the amount of substance per volume, ci (concentration) [molβV-1], related to amount, ci = = niβV-1. Advancement per volume is particularly introduced for chemical reactions, drY, where it has the dimension of a concentration. In an open system at steady-state, however, the concentration does not change as the reaction advances. Only in closed systems, specific advancement is the change in concentration divided by the stoichiometric number, ΞrY = Ξci/Ξ½i. In general, Ξci is replaced by the partial change of concentration, Ξrci, which contributes to the total change of concentration, Ξci. In open systems at steady-state, Ξrci is compensated by external processes, Ξextci, exerting an effect on the total concentration change, Ξci = Ξrci + Ξextci = 0.
Abbreviation: dtrY
Reference: Gnaiger_1993_Pure Appl Chem
Application in respirometry
- In typical liquid phase reactions the volume of the system does not change during the reaction. When oxygen consumption (Ξ½O2 = -1 in the chemical reaction) is measured in aqueous solution, then the volume-specific oxygen flux is the time derivative of the advancement of the reaction per volume [1], JV,O2 = drYO2/dt = drΞΎO2/dtβV-1 [(molβsΒ-1)βLΒ-1]. The rate of O2 concentration change is dcO2/dt [(molβLΒ-1)βsΒ-1], where concentration is cO2 = nO2βV-1. There is a difference between (1) JV,O2 [molβsΒ-1βLΒ-1] and (2) rate of concentration change [molβLΒ-1βsΒ-1]. These merge to a single expression only in a closed system. In open systems, internal transformations (catabolic flux, O2 consumption) are distinguished from external flux (such as O2 supply). External fluxes of all substances are zero in closed systems [2].
MitoPedia concepts: Ergodynamics