Partial oxygen pressure: Difference between revisions

Latest revision as of 11:36, 12 October 2022

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Partial oxygen pressure

Description

The partial oxygen pressure p_O₂ [kPa] is the contribution of the O₂ gas pressure to the total gas pressure. According to the gas law, the partial oxygen pressure is p_O₂(g) = n_O₂(g)·V·RT, where the concentration is c_O₂(g) = n_O₂(g)·V^-1 [mol·m^-3], R is the gas constant, and T is the absolute temperature, and RT is expressed in units of chemical force [J·mol^-1]. In aqueous solutions at equilibrium with a gas phase, the partial O₂ pressures are equal in the aqueous phase (aq) and gas phase (g), p_O₂(aq) = p_O₂(g) at total pressures where the partial pressure equals the fugacity. The O₂ concentration in the aqueous phase, however, is much lower than in the gas phase, due to the low oxygen solubility in water. The activity of dissolved O₂ is expressed by the p_O₂, where the solubility can be seen as an activity coefficient.

Abbreviation: p_O₂ [kPa]

Reference:

Gnaiger E (2020) Mitochondrial pathways and respiratory control. An introduction to OXPHOS analysis. 5^th ed. https://doi.org/10.26124/bec:2020-0002

SI unit: Pa = J·m^-3 = N·m^-2 = kg·m^-1·s^-2

1 atm = 760 mmHg = 101.325 kPa

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 {{MitoPedia
 |abbr=''p''<sub>O<sub>2</sub></sub> [kPa]
-|description=The '''partial oxygen pressure''' ''p''<sub>O<sub>2</sub></sub> [kPa] is the contribution of the O<sub>2</sub> gas pressure to the total gas pressure. According to the gas law, the partial oxygen pressure is ''p''<sub>O<sub>2</sub>(g)</sub> = ''n''<sub>O<sub>2</sub>(g)</sub>·''V''·''RT'', where the [[concentration]] is ''c''<sub>O<sub>2</sub>(g)</sub> = ''n''<sub>O<sub>2</sub>(g)</sub>·''V''<sup>-1</sup> [mol·m<sup>-3</sup>], ''R'' is the [[gas constant]], and ''T'' is the absolute temperature, and ''RT'' is expressed in units of chemical force [J·mol<sup>-1</sup>]. In aqueous solutions at equilibrium with a gas phase, the partial O<sub>2</sub> pressures are equal in the aqueous phase (aq) and gas phase (g), ''p''<sub>O<sub>2</sub>(aq)</sub> = ''p''<sub>O<sub>2</sub>(g)</sub> at total pressures where the partial pressure equals the fugacity. The O<sub>2</sub> concentration in the aqueous phase, however, is much lower than in the gas phase, due to the low [[oxygen solubility]] in water. The activity of dissolved O<sub>2</sub> is expressed by the ''p''<sub>O<sub>2</sub></sub>, where the [[solubility]] can be seen as an activity coefficient.
+|description=The '''partial oxygen pressure''' ''p''<sub>O<sub>2</sub></sub> [kPa] is the contribution of the O<sub>2</sub> gas pressure to the total gas pressure. According to the gas law, the partial oxygen pressure is ''p''<sub>O<sub>2</sub>(g)</sub> = ''n''<sub>O<sub>2</sub>(g)</sub>·''V''·''RT'', where the [[concentration]] is ''c''<sub>O<sub>2</sub>(g)</sub> = ''n''<sub>O<sub>2</sub>(g)</sub>·''V''<sup>-1</sup> [mol·m<sup>-3</sup>], ''R'' is the [[gas constant]], and ''T'' is the absolute temperature, and ''RT'' is expressed in units of chemical force [J·mol<sup>-1</sup>]. In aqueous solutions at equilibrium with a gas phase, the partial O<sub>2</sub> pressures are equal in the aqueous phase (aq) and gas phase (g), ''p''<sub>O<sub>2</sub>(aq)</sub> = ''p''<sub>O<sub>2</sub>(g)</sub> at total [[pressure]]s where the partial pressure equals the fugacity. The O<sub>2</sub> concentration in the aqueous phase, however, is much lower than in the gas phase, due to the low [[oxygen solubility]] in water. The activity of dissolved O<sub>2</sub> is expressed by the ''p''<sub>O<sub>2</sub></sub>, where the [[solubility]] can be seen as an activity coefficient.
 |info=* Gnaiger E (2020) Mitochondrial pathways and respiratory control. An introduction to OXPHOS analysis. 5<sup>th</sup> ed. https://doi.org/10.26124/bec:2020-0002
 }}