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Partial oxygen pressure

From Bioblast


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Partial oxygen pressure

Description

The partial oxygen pressure pO2 [kPa] is the contribution of the O2 gas pressure to the total gas pressure. According to the gas law, the partial oxygen pressure is pO2(g) = nO2(g)VRT, where the concentration is cO2(g) = nO2(g)V-1 [mol路m-3], R is the gas constant, and T is the absolute temperature, and RT is expressed in units of chemical force [J路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), pO2(aq) = pO2(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 pO2, where the solubility can be seen as an activity coefficient.

Abbreviation: pO2 [kPa]

Reference:


SI unit: Pa = J路m-3 = N路m-2 = kg路m-1路s-2
1 atm = 760 mmHg = 101.325 kPa