Equilibrium partial pressure of oxygen

Figure 6.17 Composition of Ti02 reduced by Coulombic titration to TiOv plotted versus the corresponding equilibrium partial pressure of oxygen, determined by cell voltage, for a sample at 900°C. [Data taken from D-K. Lee, J-I. Jeon, W. Choi, and H-I. Yoo, J. Solid State Chem., 178, 185-193 (2005).]...

A metal-metal oxide mixture A with a low equilibrium partial pressure of oxygen is sealed in a vacuum and heated to a temperature T. A metal-metal oxide mixture B with a high equilibrium partial pressure of oxygen is treated similarly. If the two containers are linked so that there is a free interchange of gas, what will be the final solids present ... 

Significant curvature may be observed in the case of lifetime- (and intensity-) based sensors, mainly when the relation knri [Parameter]) is not linear. Figure 9.4 shows this type of nonlinear behavior for a fiberoptic oxygen sensor. The figure shows Stern-Volmer-type plots (r l versus [02]) at four different temperatures. The curvature is caused by the inability of the carrier to transport oxygen proportionally to the equilibrium partial pressure of oxygen. 

If/represents the fraction of myoglobin molecules bearing oxygen and P represents the equilibrium partial pressure of oxygen then... 

Equilibrium of the system containing MnO(s), Mn304(s) and 02(g) was examined. Both MnO and Mn304 were pure and stable states. It was found that equilibrium partial pressures of oxygen were... 

FIG. 200. The conditions for the formation of magnetite Fc304 (Smiltens, 1952). The numbers on the curves specify the equilibrium partial pressure of oxygen in MPa at various CO CO2 ratios. 

Estimate the equilibrium partial pressures of oxygen for the oxidation of chromium and aluminum at lOOO C. 

The phase equilibria between Pi-Ni3S2, p2-Ni4S3, and NiS(a) were studied by measuring the equilibrium partial pressure of oxygen as a function of temperature. 

It was established that the electrical conductivity of the studied materials was determined by a non stoichiometric disordering and could he regulated in considerable extent by doping and changing equilibrium partial pressure of oxygen in gas phase. 

The transport of oxygen in hemoglobin solutions is similarly a more complex process than diffusion with the reaction A 4 B = AB, as it has most often been modelled. The extent of oxyhemoglobin formation varies sigmoidally, rather than hyperbolically with the equilibrium partial pressure of oxygen, a consequence of coopera-tive oxygen binding at the four sites per protein molecule (29). 

That means for a certain temperature, the equilibrium partial pressure of oxygen of an oxide metal mixture is constant. This allows to use such systems as reference systems. 

Calculate the equilibrium constant and equilibrium partial pressure of oxygen for the reaction... 

Figure 4. Plot of equilibrium partial pressure of oxygen, log versus x in (FejOJ, -, (Fe2Zn04) , at 1100°. This delineates the width of the phase field between reduction boundary (zinc ferrite, zinc wiistite) and oxidation boundary (zinc ferrite, zinc hematite). The center curve relates to the equilibrium fugacity for zinc ferrites with the ideal 4 3 oxygen metal ratio. Pressures in atm.

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