Difference between revisions of "Advancement per volume"
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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'' [mol∙''V''<sup>-1</sup>], is related to [[advancement]], d<sub>tr</sub>''Y'' = d<sub>tr</sub>''ξ''∙V<sup>-1</sup>, as is the amount of substance per volume, ''c''<sub>i</sub> ([[concentration]]) [mol∙''V''<sup>-1</sup>], related to [[amount]], ''c''<sub>''i''</sub> = = ''n''<sub>i</sub>∙''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, Δ<sub>r</sub>''Y'' = Δ''c<sub>i</sub>''/''ν<sub>i</sub>''. In general, Δ''c<sub>i</sub>'' is replaced by the partial change of concentration, Δ<sub>r</sub>''c<sub>i</sub>'', which contributes to the total change of concentration, Δ''c<sub>i</sub>''. In open systems at steady-state, Δ<sub>r</sub>''c<sub>i</sub>'' is compensated by external processes, Δ<sub>ext</sub>''c<sub>i</sub>'', exerting an effect on the total concentration change, Δ''c<sub>i</sub>'' = Δ<sub>r</sub>''c<sub>i</sub>'' + Δ<sub>ext</sub>''c<sub>i</sub>'' = 0. | ||
|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 (''ν''<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>''ξ''<sub>O2</sub>/d''t''∙''V''<sup>-1</sup> [(mol∙s<sup>-1</sup>)∙L<sup>-1</sup>]. The rate of O<sub>2</sub> concentration change is d''c''<sub>O2</sub>/d''t'' [(mol∙L<sup>-1</sup>)∙s<sup>-1</sup>], where concentration is ''c''<sub>O2</sub> = ''n''<sub>O2</sub>∙''V''<sup>-1</sup>. There is a difference between (''1'') ''J''<sub>''V'',O2</sub> [mol∙s<sup>-1</sup>∙L<sup>-1</sup>] and (''2'') rate of concentration change [mol∙L<sup>-1</sup>∙s<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
- high-resolution terminology - matching measurements at high-resolution
Advancement per volume
Description
Advancement per volume or volume-specific advancement, dtrY [mol∙V-1], is related to advancement, dtrY = dtrξ∙V-1, as is the amount of substance per volume, ci (concentration) [mol∙V-1], related to amount, ci = = ni∙V-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, ΔrY = Δci/νi. In general, Δci is replaced by the partial change of concentration, Δrci, which contributes to the total change of concentration, Δci. In open systems at steady-state, Δrci is compensated by external processes, Δextci, exerting an effect on the total concentration change, Δci = Δrci + Δextci = 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 (νO2 = -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 = drξO2/dt∙V-1 [(mol∙s-1)∙L-1]. The rate of O2 concentration change is dcO2/dt [(mol∙L-1)∙s-1], where concentration is cO2 = nO2∙V-1. There is a difference between (1) JV,O2 [mol∙s-1∙L-1] and (2) rate of concentration change [mol∙L-1∙s-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
