Order of reactants

Power law expressions are useful as long as the approximate orders of reactant concentration are constant over a particular concentration course. A change in the order of the reaction corresponds to a change in the surface concentration of a particular reactant. A low reaction order usually implies a high surface concentration, a low reaction order, and a low surface reaction of the corresponding adsorbed intermediates. In order to deduce (Eq. (1.17b)) the rate of surface carbon hydrogenation, the power law of Eq. (1.18) has been used. 

Order (of reactant) The positive or negative exponent, determined through an experiment, of the reactant concentration in a rate law. 

An equation giving the concentration of a reactant remaining after a specified time has different mathematical form for different orders of reactants. 

The experimentally determined reaction orders of reactants indicate the number of molecules of those reactants involved in (1) the slow step only, if it occurs first, or (2) the slow step and any fast equilibrium steps preceding the slow step. 

Table 18.1 Yields of condensation product after cyclic permutations of the order of reactant introduction...

Enzyme catalysis can be studied from various points of view regulation, structural aspects, order of reactant binding and product release, the role of functional residues (e.g., general bases or acids), etc. This chapter presents the use of kinetic isotope effects (KIEs) as tools for studying the physical nature of enzyme catalyzed C-H bond activation. 

Reaction orders of reactants may be negative, possibly causing self-acceleration within some conversion range. Such behavior requires involvement of at least two catalytic sites and tends to arise if the respective reactants is the macs or at least is very strongly adsorbed. 

Order (of reactant) the positive or negative exponent, determined by experiment, of the reactant concentration in a rate law. (12.2) Organic acid an acid with a carbon-atom backbone often contains the carboxyl group. (14.2)... 

Two- and three-step arrangements of micromixers are also of interest for the generation of nanopartides of binary and complex composition. They can be realized for continuous flow processes and for segmented flow applications (Figure 17.10). The order of reactant application, the flow rates and flow rate ratios determine the properties of the colloidal product solution obtained. Strong dependences of the... 

As the gelation pH of silica has a drastic effect on the size of the elementary particles of silica (1) its influence has been evaluated for different addition durations. In the case of the semi-continuous process the gelation pH is easily modified by changing the ratio of the reactant fluxes. For the batch process the order of reactant introduction in the reactor must be changed to have an acid pH (silicate poured in acid) or a base pH (acid poured in silicate). As complex modifications can arise in the reaction mechanisms when the order of reactant addition is changed (18) this latter case has not been studied in this work. 

The above reactions (Eq. 2.44) are freqnently not straightforward a plethora of different (generally nnnsnal) products are generated in such reactions even by slight variations in the experimental conditions/manipniations, the order of reactant(s) addition, the stoichiometry of reactants,and the nature of the alkoxide groups. Although there appears to be little synthetic control over the natnre or stmctnres of the prodncts, an impressive series of stmctnrally novel species have been obtained via reactions of alkali metal alkoxides with the appropriate lanthanide chloride or ceric ammoninm nitrate, as illustrated below. 

So far, we have considered two types of experiments for studying reaction mechanisms. First was an analysis of kinetics (Chapter 7), which can give the order of reactants involved in a mechanism prior to or during the rate-determining step. Second, we now have a method to determine if a bond to hydrogen has been broken or rehybridized. This latter experiment gives us some limited structural information about the activated complex. 

Much of the evidence for proposed mechanisms of reactions come from kinetic studies that identify the products and intermediates formed during a reaction, as well as determining the individual orders of reactants and overall order of the reaction. Other evidence for reaction mechanisms comes from stereochemical studies which follow the changes in shape that occur as... 

Effect on Ionic Strength on Kinetic Orders of Reactants... 

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