Stoichiometry of reaction

The importance of knowing the stoichiometry of a reaction can be simply illustrated by considering the aquation of c -Cr(en)2(NCS)Cl+ ion.Is Cl or NCS replaced in the initial step and is the product cis or trans or both Does the product of this first step aquate further, and if so what groups are then replaced Chemical and spectral analysis answers these questions. The results reveal the surprising fact that the bidentate ligand en is lost at one stage, a behavior that appears more common with ammines of Cr(III) than with Co(III), where its occurrence is only occasionally noted. 

Inconsistencies in the values of equilibrium constants obtained from measurements on systems at equilibrium with those derived from rate measurements may also reveal unexpected reaction paths. See Chap. 8, Pd(II). 

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The composite of sequences a, f3, and y gives the overall stoichiometry of reaction (8-56). The steady-state approximations, abbreviated as before, are... 

Figure 6.4c showed the storage uptake behaviour by using N0/02 over the reference Pi-lia/y-AEOj sample. Upon admission of NO (at = 0 s) both the NO and N02 outlet concentrations show a significant delay. Then the NO concentration increases, followed by that of N02. N02 formation is ascribed to the oxidation of NO by 02 according to the stoichiometry of reaction (2) ... 

The second approach (Equation(3)) has a number of advantages over the first one (Equation(2)). The alkyl complexes are more reactive than the related alkoxides, the latter being for group 4 elements generally associated into dimers or trimers 48 also, reaction (2) liberates an alcohol which may further react with the surface of silica, whereas the alkane ( Equation(3)) is inert. It was demonstrated by various spectroscopic techniques and elemental analysis that with a silica dehydroxylated at 500 °C under vacuum, the stoichiometry of reaction (3) corresponds to n = 1.45,46 Moreover, a better control of the surface reaction was achieved with the procedure represented in Equation(3). 

They allow close control over the stoichiometries of reactions, even at elevated temperatures. 

But the reaction conditions are still more complicated because the stoichiometry of reaction might alter. Many greases and oils comprise the esters of long-chain fatty acids. The hydrolysing reaction between NaOH and an ester such as ethyl ethanoate proceeds with a stoichiometry of 1 1, but a tri-ester, such as most natural oils (e.g. olive oil or sunflower oil), occurs with a 1 3 stoichiometry, consuming one hydroxide ion per ester bond. Clearly, the hydroxide will be consumed more quickly when hydrolysing a triester than a mono-ester. The rate depends on the stoichiometry of reaction. 

Bromine readily adds across an alkenic double bond by electrophilic addition (Figure 8.4). The brominated compound is usually colourless, but bromine in solution ( bromine water ) has a red colour. Addition of bromine water to an aikene is accompanied by a loss of the red colour as reaction proceeds. The stoichiometry of reaction is almost always 1 1, with one molecule of bromine reacting per double bond. 

After combining all these equations, the overall conversion of biomass into hydrocarbon or methanol adopts the stoichiometry of Reactions (6) and (7) ... 

The preparation of U(CsH5)2Cl2 91) and U(C5Hs)Cl3 -DME 92) were reported shortly after thallium(I) cyclopentadienide was found to be useful in controlhng the stoichiometries of reactions with uranium and thorium tetrachloride 93, 94). 

Selected entries from Methods in Enzymology [vol, page(s)] Association constant determination, 259, 444-445 buoyant mass determination, 259, 432-433, 438, 441, 443, 444 cell handling, 259, 436-437 centerpiece selection, 259, 433-434, 436 centrifuge operation, 259, 437-438 concentration distribution, 259, 431 equilibration time, estimation, 259, 438-439 molecular weight calculation, 259, 431-432, 444 nonlinear least-squares analysis of primary data, 259, 449-451 oligomerization state of proteins [determination, 259, 439-441, 443 heterogeneous association, 259, 447-448 reversibility of association, 259, 445-447] optical systems, 259, 434-435 protein denaturants, 259, 439-440 retroviral protease, analysis, 241, 123-124 sample preparation, 259, 435-436 second virial coefficient [determination, 259, 443, 448-449 nonideality contribution, 259, 448-449] sensitivity, 259, 427 stoichiometry of reaction, determination, 259, 444-445 terms and symbols, 259, 429-431 thermodynamic parameter determination, 259, 427, 443-444, 449-451. 

On the basis of these data, the following mechanism for reduction by hydrogen can be suggested. H2, activated over the Pt sites according to the Pt-catalyzed pathway discussed previously, reduces the stored nitrates directly to ammonia or, more likely, induces the decomposition of nitrates to gaseous NO, which are then reduced by H2 to NH3 over the Pt sites [overall reaction (13.47)]. Once ammonia has been formed, it can react with adsorbed nitrates and this reaction is very selective towards nitrogen. It is worth noting that the reaction of ammonia with NOx obeys the stoichiometry of reaction (13.49), which is different from that of the well-known NH3-NO SCR reaction because it implies the participation of nitrates. 

A similar pathway for the reduction of stored nitrates has been presented [136-138]. Here the importance of the integral behavior of the reactor is underlined but the occurrence of a regeneration front instead of a hydrogen front is suggested, whereas an in-series/parallel scheme is proposed and the stoichiometry of reaction (13.49) is not recognized. 

Also, from the stoichiometry of Reaction 1 it is true that, at time t,... 

The stoichiometries of reactions 2 to 5 are based on the amounts of reagents used in reaction 1 and all yields are calculated on the basis of the platinum complex used in reaction 1. The complex trans-[PtHCl(PEt3)2] is prepared according to the procedure given in Ref. 11. 

Solution The stoichiometry of Reaction 6-19 tells us that H and OH are produced in a 1 1 molar ratio. Their concentrations must be equal. Calling each concentration x, we can write... 

The key step in solving the problem is to prepare a table showing initial concentrations and final concentrations after equilibrium is attained. Let s say that x mol of lOj are consumed in the reaction. From the stoichiometry of Reaction 6-41, we know that 10 mol... 

Exactly enough Ce4+ has been added to react with all the Fe2+. Virtually all cerium is in the form Ce3+, and virtually all iron is in the form Fe3+. Tiny amounts of Ce4+ and Fe2+ are present at equilibrium. From the stoichiometry of Reaction 16-1, we can say that... 

Stoichiometry of Reaction of Metal Hydrocarbyls with Supports. 

Table II. Stoichiometry of Reaction of Metal Hydrocarbyls with Silica and Alumina Supports (41, 42, 43)...

Stoichiometry of Reaction. One of the factors that has made this a particularly attractive system for study has been the unambiguous identification and structural characterization of the starting tricoordinate dicopper(I) complex [Cu2(R—XYL—H)]2+ (10, R = H) and the green product... 

The stoichiometry of reaction (14) is reminiscent of the electroreduction of 02 to H20. It is of interest that oxygenation of vanadium(III) gives oxovanadi-um(V), whereas multiple one-electron redox centers have been considered to be essential for the incorporation of 02. An explanation for this can be found in... 

Stoichiometry of reaction and nomenclature. Stoichiometry refers to the number of moles of a chemical component reacting to form a species. Consider the reaction... 

The reasons for this are not clear (40). I5N-Labeling studies on the protonation reaction between HBr and Mo(N2)2(PPh3)(triphos)] show that the dinitrogen released in both fast and slow stages is formed without new N—N bonds being formed. These observations together with the prerequisite for a monotertiary phosphine and the stoichiometry of reaction (49) have been rationalized by an intramolecular redox reaction such as is represented by Scheme 13 (40). However, certain aspects of this Scheme have yet to find empirical support. 

The determination of the stoichiometry of reaction 5 (most often leading to singly or doubly bonded species) is usually based on the measurement of the amounts of anchored metal and Cl on the catalyst, or HCI evolved during the reaction [19-24],... 

Section 12.1 introduces the concept of pressure and describes a simple way of measuring gas pressures, as well as the customary units used for pressure. Section 12.2 discusses Boyle s law, which describes the effect of the pressure of a gas on its volume. Section 12.3 examines the effect of temperature on volume and introduces a new temperature scale that makes the effect easy to understand. Section 12.4 covers the combined gas law, which describes the effect of changes in both temperature and pressure on the volume of a gas. The ideal gas law, introduced in Section 12.5, describes how to calculate the number of moles in a sample of gas from its temperature, volume, and pressure. Dalton s law, presented in Section 12.6, enables the calculation of the pressure of an individual gas—for example, water vapor— in a mixture of gases. The number of moles present in any gas can be used in related calculations—for example, to obtain the molar mass of the gas (Section 12.7). Section 12.8 extends the concept of the number of moles of a gas to the stoichiometry of reactions in which at least one gas is involved. Section 12.9 enables us to calculate the volume of any gas in a chemical reaction from the volume of any other separate gas (not in a mixture of gases) in the reaction if their temperatures as well as their pressures are the same. Section 12.10 presents the kinetic molecular theory of gases, the accepted explanation of why gases behave as they do, which is based on the behavior of their individual molecules. 

The first term of Eq. 80 represents the mass loss of char particles due to carbon combustion and the second term represents the mass loss of char particles due to sulfur reaction with oxygen. Using the stoichiometry of reactions 1 and 2, we can obtain the moles of oxygen used up in these respective reactions for any arbitrary height n as. 

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