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Reaction stoichiometry consecutive reactions

For multiple reactions, material balances must be made for each stoichiometry. An example is the consecutive reactions, A = B = C, for which problem P4.04.52 develops a closed form solution. Other cases of sets of first order reactions are solvable by Laplace Transform, and of course numerically. [Pg.262]

Starting with separate feeds of reactant A and B of given concentration (no dilution with inerts permitted), for the competitive-consecutive reactions with stoichiometry and rate as shown... [Pg.201]

Reaction stoichiometry and mechanism. This process, which selectively produces linear alcohols ranging fhom to about C ,is based on the chemical reactions of Table IT. Main reactions (fa,b) produce alcohols and their related unavoidable by-products, CO and H O, the former being favored at low H /CO ratios due to side or consecutive shift reaction (c). Secondary reactions produce light hydrocarbons (d,e). The reactions stoichiometry (H /CO) varies between 0.6 and 3, depending on the nature of the products and the number of carbon atoms involved. Most of these reactions are strongly exothermic. [Pg.43]

The most significant factor of alkali-catalyzed transesterification was the molar ratio of the alcohol and oil. The stoichiometry of alkali-catalyzed transesterification requires 3 mol of alcohol/1 mol of triglyceride to generate 3 mol of FAME and 1 mol of glycerol. Since the transesterification is composed of reversible and consecutive reactions, the increase in molar ratio of methanol will result in high conversion yields. [Pg.753]

On the other hand, in the usual type of consecutive reaction involving product as a reactant, the initial rate is not the maximum observed since the rate increases as product is formed for this reason, the initial rate is increased by the addition of the product at the beginning of the reaction and the stoichiometry alters as the reaction proceeds. For this type of reaction, we require an equation of the type set out in eqn. (84), namely... [Pg.399]

Determination of the temperature interval at which each contributory reaction occurs TG can provide a rapid and effective method of qualitatively establishing a pattern of reactivity and determining whether an overall change proceeds as a single process or through a sequence of consecutive steps. Mass losses at each step, as a fraction of the total, can be used as a qualitative indication of reaction stoichiometries and the temperature interval recorded. Such preliminary conclusions should be regarded as requiring analytical or structural confirmation, EGA, or x-ray diffraction. [Pg.156]

In all the reactions listed in Table I it is assumed that C is the preferred product. Intermediate steps involving excited species are omitted so that the equations merely represented the overall stoichiometry of the various situations. If, therefore, product C is being produced from reactants A and B and a second (consecutive) reaction is present which destroys C, then the rate of the second reaction can be reduced by main- ... [Pg.389]

When a mixture of various species is present in a reaction vessel, one often has to worry about the possibility that several reactions, not just a single reaction, may occur. If one is trying to study one particular reaction, side reactions may complicate both chemical analysis of the reaction mixture and mathematical analysis of the raw data. The stoichiometry of the reaction involved and the relative importance of the side reactions must be determined by qualitative aud quantitative analyses of the products of the reaction at various times. If one is to observe the growth and decay of intermediate products in consecutive reactions, measurements must be made on the reaction system before the reaction goes to completion. [Pg.30]

Eqnations of this form can be written for each of the various products of the reaction, as well as for consnmption of the limiting substrate. Additional stoichiometric relations can also be developed for other species that are ntilized as nonlimiting substrates by the microorganism nndergoing fermentation. However, because the stoichiometry associated with the production of biomass is well established for only a very few simple fermentations, biochemists and others engaged in the design of bioreactors find it useful to employ the concept of yield coefficients in their efforts to analyze the performance of proposed bioreactors. In essence, these researchers determine the yield coefficients experimentally in a manner akin to the technique of eliminating time as a variable in considerations of competitive and consecutive reactions (see Chapter 9). [Pg.462]

The rate profiles, stoichiometry, and reaction product distributions are often extremely complicated. Thus, for the seemingly innocent [ o(bpy)3] plus r " reaction, there are four consecutive rate steps that can be observed and the product mixture contains [ r2(bpy)(OH)2(OH2)6] , [ o(OH2)6] - , [ o(bipy)(OH2)4], bpy, and reduced bpy. In many cases, radical-ion mechanismsare involved, accounting for the observed complexities. [Pg.126]

It was found that the hydrogen-producing activity of catalysts declined during consecutive reduction and oxidation cycles. The authors concluded that the catalyst deactivation could be prevented by careful balancing of the stoichiometry of the reduction oxidation reactions. The amount of H2 produced was estimated at 210 Nm1 2 3/kL of vacuum HRO [57],... [Pg.65]

AI2O3 is initially <3, as expected from reaction (13.37), which indicates that the NO2 uptake at the beginning of the pulse does not obey the overall stoichiometry of the reaction. This has been explained in the literature, considering that the NO2 disproportionation consists of consecutive elementary steps and that the first step is faster than the following ones, which account for the evolution of NO (Equations 13.38-13.40) [94] ... [Pg.416]

Oxidation by dioxygen has a fundamental difficulty. The molecule has a diatomic structure, while in most cases only one atom is needed for selective oxidation of organic compounds. Even in the case of more complex reactions, the stoichiometry of which requires several (and sometimes many) oxygen atoms, the oxidation process on a catalyst surface is likely to proceed step by step, involving consecutively one oxygen atom after another. [Pg.217]

A complex network of reactions is hidden behind the simple stoichiometry of -butane oxidation (Equation 35). Butene, butadiene and furan have been suggested to be intermediates in a cascade of reactions eventually producing the anhydride. Carboxylic acids and carbon oxides are formed in parallel and consecutive oxidations. [Pg.58]

Of these, only the first case can be treated exactly. Let us consider a scheme of two consecutive first-order reactions with stoichiometry given by... [Pg.33]

Etching of InP in iodic acid solutions also proceeds via a chemical mechanism involving consecutive steps [92]. By analogy with the case of GaP/Br2, the stoichiometry of the etching reaction was identified as ... [Pg.40]

Titration curves for rosmarinic acid in (he presence of different concentrations of iron ions indicate a stoichiometry of 1 to 1 for the complex. These data were confirmed by elemental analysis and inductively coupled plasma emission spectrometry (70. This 1 to 1 complex seems to be the only absorbent species in the reaction media. Support of this assertion come from graphical analysis of the consecutive spectra according to Coleman et al. (Jd) and from HPLC analysis of the reaction media (Figure 6). From this figure, it can also be deduced that, under the assay conditions, almost all rosmarinic acid is forming part of the complex, since absorbance at 333 nm for the expected retention time of rosmarinic acid is very low. [Pg.240]

M. R. Newberger and R. H. Kadlec [AIChE J., 17,1381-1387 (1971)] studied the conditions for optimal operation of a tubular reactor in which consecutive second-order reactions are being carried out. Of particular interest was the saponification of diethyl adipate with sodium hydroxide in aqueous solution. The stoichiometry of these reactions can be expressed as... [Pg.298]

In contrast with the n = 6 systems, a nucleophUic reactivity might be anticipated for the more electron-rich metallonitrosyls. Although nitrosyl protonation reactions seem not to occur at the MNO moieties (there are at most reports on hydrogen bonds being estabhshed with distal histidines. Ref (45)), the reaction of Mb NO with O2 showed the formation of 15103 (145). The decay of [Fe(CN)5(NO)] upon consecutive additions of dissolved O2 corresponds to the following stoichiometry ... [Pg.120]


See other pages where Reaction stoichiometry consecutive reactions is mentioned: [Pg.14]    [Pg.15]    [Pg.110]    [Pg.230]    [Pg.382]    [Pg.193]    [Pg.29]    [Pg.148]    [Pg.590]    [Pg.167]    [Pg.181]    [Pg.13]    [Pg.214]    [Pg.153]    [Pg.6561]    [Pg.83]    [Pg.10]    [Pg.192]    [Pg.6560]    [Pg.126]    [Pg.60]    [Pg.135]   
See also in sourсe #XX -- [ Pg.131 , Pg.132 , Pg.133 , Pg.134 , Pg.134 , Pg.135 , Pg.135 , Pg.136 ]




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