Oxygen over stoichiometry

Upon admission of 1000 ppm NO in the presence of3%v/v oxygen over the Pt-Ba/ Y-AI2O3 sample (Figure 13.12c), both the NO and NO2 outlet concentrations show a significant delay. Then the NO concentration increases, followed by that of NO2. NO2 formation is ascribed to the oxidation of NO by O2 according to the stoichiometry of reaction (13.41) ... 

The reaction of ammonia with oxygen over V-based catalysts produces mainly nitrogen, according to the stoichiometry of R5 in Table V. Analogously to the case of the ammonia adsorption-desorption, specific runs were carried out in order to extract the intrinsic kinetics of ammonia oxidation and at the same time to validate the previously fitted kinetics of the ammonia adsorption-desorption process. 

This research group obtained kinetic data using a well-agitated pressure vessel in which the partial pressure of oxygen over the liquid was maintained constant by continuous addition of oxygen as the reaction proceeded. For our present purpose, we may consider the stoichiometry of the reaction to be of the general form... 

H2 Yield = Molar ratio between the hydrogen stream in the permeate side and the total hydrogen thera-etically (n-oducible from the stoichiometry of reaction. " Oxygen over glycerol feed ratio. 

The kinetics of the oxidation of chromium(II) by vanadium(ni) in acid perchlorate media have been studied spectrophotometrically between 0.2° and 35.0 °C over a range of 0.027-0.500 M HC104 . The oxygen-sensitivity of both reactants meant that the air had to be excluded in all kinetic runs. Also, since V(III) slowly reduces perchlorate ion, fresh solutions of V(III) were required for each experiment. In terms of stoichiometry the reaction conforms accurately to... 

Another type of gas law problem involves stoichiometry. Gas stoichiometry problems are just like all other stoichiometry problems—you must use moles. In addition, one or more gas laws are necessary. Let s look at a gas stoichiometry problem. What volume, in liters of oxygen gas, collected over water, forms when 12.2 g ofKCl03 decompose according to the following equation ... 

The first two determinations by radiation absorption require accurate measurements of the extinction coefficients of ozone (a measurement of the absorption efficiency of the incoming radiation at a maximal absorption wavelength) in the ultraviolet and the infrared. Three different principles have been used over the last 20 years to measure the extinction coefficient of ozone in the ultraviolet at 254 nm manometric, decomposition stoichiometry, and gas-phase titration. The manometric method, which is based on pressure measurements of gaseous ozone, requires (in at least one case ) a substantial and somewhat uncertain correction for decomposition and the method of decomposition stoichiometry depends on the pressure change that accompanies the decomposition of ozone to oxygen, 20, 30,. Clyne and Coxon determined ozone... 

The oxidation of fluorene in basic solution is in sharp contrast to diphenylmethane. Figure 1 emphasizes the clean stoichiometry observed in the oxidation of fluorene (one mole of oxygen per mole of fluorene). The over-all reaction for fluorene apparently involves Reactions 1, 2, 6, and 5 (18). 

The studies on Cu2 aO mentioned above concluded that CujO is a metal-deficient p-type semiconductor with cation vacancies. It was not established, however, which kinds of defects (Vcu, Vcu) were dominant and what the effect of Q (interstitial oxygen) was on non-stoichiometry. To clarify these points, Peterson and Wiley measured the diffusion coefficient, D, of Cu in Cu2 O, by use of "Cu as a tracer over the temperature range 700-1153 °C and for oxygen partial pressures, greater than 10 atm. It has been widely accepted that lattice defects play an important role in the diffusion of atoms or ions. Accordingly it can be expected that the measurement of D gives important information on the lattice defects. 

Great care should be exercised in formulating any assumptions pertaining to the stoichiometry of the reactions. For example, in the models used herein, the final results are critically dependent upon the relation between the oxygen consumed and the fuel consumed and how the flame temperature is assumed to vary with the fuel consumed. The range—i.e., lean and/or rich fuel-air ratios—over which the needed assumption must be valid should be thoroughly investigated. 

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