Stoichiometry limiting factors

For high-sulfur bituminous coal containing 4.0 weight percent sulfur, the scrubber inlet S02 concentration is about 2800 ppm, and the required outlet S02 for 90 percent removal is 280 ppm. S02 back-pressure should not be a limiting factor for a scrubber inlet pH of at least 5.0 with an outlet pH of at least 4.6. Thus, limestone stoichiometries as low as 1.1 are feasible with high-sulfur coal and a well-designed scrubber system. 

You must arrive at the same conclusion as to the identity of the limiting factor no matter which approach you use. Typical limiting-factor stoichiometry problems ask for three things ... 

The amount of product is calculated by the same method used earlier for mole-to-gram stoichiometry problems. Start with the moles of the limiting factor because a limiting factor is defined as the reactant that limits or determines the amount of product that can be made. 

The methodical limitations concern analyte recovery (in the case of peak-area-changes assays), peak identification, and in understanding the interplay between binding rates and separation parameters. Perhaps the most limiting factor for using the technique outside specialist laboratories is the fact that ACE is not one, but a suite of different techniques united by a capillary electrophoretic separation step. Furthermore, in the case of unknown stoichiometry, only absolute dimensions of the binding constants are accessible. 

During this reaction, the oxidation state of iodate ions goes from +V to 0. It is a process sometimes called aftve-electron iodatometry (see the next chapter). In order to standardize thiosulfate solutions and since potassium iodate is a primary standard, its concentration must be the limiting factor of the reaction. This means that there must be an excess of iodide ions and of protons in comparison to iodate ions, when the reaction stoichiometry is taken into account. In other words, for exactly one mole of potassium iodate weighed, we must add more than five moles of iodide ions and more than six moles of protons. It is not necessary to know their exact numbers provided they obey the above conditions. In these conditions, exactly three moles of iodine are prepared from one mole of iodate. Figure 18.4 summarizes these considerations. 

The selectivity here is directly proportional to complex formation constants and can be estimated, once the latter are known. Several methods are now available for determination of the complex formation constants and stoichiometry factors in solvent polymeric membranes, and probably the most elegant one is the so-called sandwich membrane method [31], Two membrane segments of different known compositions are placed into contact, which leads to a concentration polarized sensing membrane, which is measured by means of potentiometry. The power of this method is not limited to complex formation studies, but also allows one to quantify ion pairing, diffusion, and coextraction processes as well as estimation of ionic membrane impurity concentrations. 

Unless all these factors are taken into account, it is usually more appropriate to refer to the results of a flow cytometric analysis in terms of antibodies bound per cell rather than antigens per cell. Stoichiometry will be even less certain with multivalent IgM antibodies the usually low monovalent affinity and strong role of avidity in the binding of IgM antibodies make them of limited value for antigen quantitation. Theoretically, the most precise alternative would be the use of directly labeled monovalent antibody fragments, which would avoid problems of variable stoichiometry. However, in addition to the inconvenience of producing suitable labeled monovalent antibody fragments, the increased off rate of monovalently bound antibody may make analysis more difficult. 

Semilogarithmic plots of formation pressure versus reciprocal absolute temperature yield straight lines, over limited temperature ranges, for hydrate formation from either liquid water, or ice. From Equation 4.13 such linear plots either indicate (1) relatively constant values of the three factors (a) heat of formation, AH, (b) compressibility factor, z, (c) stoichiometry ratios of water to guest or (2) cancellation of curvilinear behavior in these three factors. 

The luminescence characteristics of four complexes formed with arsenazo (I and II) and thorin (I and II) dyes (fig. 67) as well as those of the corresponding ternary complexes with phen have been investigated in aqueous solution. In presence of Ybm ions, 1 1 complexes are formed, except for thorin I, which yields a 1 2 (Yb L) complex. As a consequence, for thorin I only one phen molecule is present, yielding a 1 2 1 (Yb L phen) ternary complex, while 1 1 2 stoichiometries are observed for the three other complexes. Addition of phen results in a significant enhancement (2- to 7-fold) of the luminescence quantum yields, which reach a maximum value of 0.13% for the complex with arsenazo I. As a consequence, the detection limits are lowered by similar factors, from 2 to 8. 

After a decade of intensive development, ACE is widely recognized nowadays as a powerful tool in the study of different kinds of biomolecular interactions. More than 400 scientific reports related to ACE can be found in the literature, covering almost all fields of bioanalytical chemistry. Unique features of homogeneous analysis coupled with the separation power of CE makes ACE especially favorable for precise determination of affinity parameters, such as binding constants and binding stoichiometries. Automation, multicapillary arrows, and chip technology increase throughput of ACE analysis, a factor which still limits... 

Implied in the stoichiometry of their preparation is the full equivalent of transition metal relative to substrate. Indeed, to this day, cuprates tend to be used in excess in most smaller scale reactions. Over the past decade, however, there has been a noticeable shift toward development of methodology catalytic in Cu(I). The rationale behind the emphasis is in line with the times that is, environmental concerns have come to the fore, placing implied limits on the extent of transition metal usage. Therefore, notwithstanding favorable economic factors associated with copper, it being a base rather than precious metal, much effort has been devoted toward copper-catalyzed reactions, including cross-couplings to arrive at C-N, C-O, and C-H, in addition to C-C bonds. Moreover, tremendous strides have been made in asymmetric versions of perhaps the most fundamental of cuprate reactions 1,4-additions to Michael acceptors. 

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