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Rate determination

The treatment may be made more detailed by supposing that the rate-determining step is actually from species O in the OHP (at potential relative to the solution) to species R similarly located. The effect is to make fi dependent on the value of 2 and hence on any changes in the electrical double layer. This type of analysis has permitted some detailed interpretations to be made of kinetic schemes for electrode reactions and also connects that subject to the general one of this chapter. [Pg.214]

The measurement of a from the experimental slope of the Tafel equation may help to decide between rate-determining steps in an electrode process. Thus in the reduction water to evolve H2 gas, if the slow step is the reaction of with the metal M to form surface hydrogen atoms, M—H, a is expected to be about If, on the other hand, the slow step is the surface combination of two hydrogen atoms to form H2, a second-order process, then a should be 2 (see Ref. 150). [Pg.214]

The sequence of events in a surface-catalyzed reaction comprises (1) diffusion of reactants to the surface (usually considered to be fast) (2) adsorption of the reactants on the surface (slow if activated) (3) surface diffusion of reactants to active sites (if the adsorption is mobile) (4) reaction of the adsorbed species (often rate-determining) (5) desorption of the reaction products (often slow) and (6) diffusion of the products away from the surface. Processes 1 and 6 may be rate-determining where one is dealing with a porous catalyst [197]. The situation is illustrated in Fig. XVIII-22 (see also Ref. 198 notice in the figure the variety of processes that may be present). [Pg.720]

B. Reaction within the Adsorbed Film as the Rate-Determining Step... [Pg.722]

The above equations can apply when the rate-determining step is first order even though the complete reaction mechanism is complicated. Thus for the reac-... [Pg.725]

Some early observations on the catalytic oxidation of SO2 to SO3 on platinized asbestos catalysts led to the following observations (1) the rate was proportional to the SO2 pressure and was inversely proportional to the SO3 pressure (2) the apparent activation energy was 30 kcal/mol (3) the heats of adsorption for SO2, SO3, and O2 were 20, 25, and 30 kcal/mol, respectively. By using appropriate Langmuir equations, show that a possible explanation of the rate data is that there are two kinds of surfaces present, 5 and S2, and that the rate-determining step is... [Pg.741]

Fig. 1. The rate-determining step in the neutral hydrolysis of paramethoxy-phenyl dichloroacetate. In the reactant state (a) a water molecule is in proximity of the carbonyl carbon after concerted proton transfer to a second water molecule and electron redistribution, a tetrahedral intermediate (b) is formed. Fig. 1. The rate-determining step in the neutral hydrolysis of paramethoxy-phenyl dichloroacetate. In the reactant state (a) a water molecule is in proximity of the carbonyl carbon after concerted proton transfer to a second water molecule and electron redistribution, a tetrahedral intermediate (b) is formed.
Melander first sought for a kinetic isotope effect in aromatic nitration he nitrated tritiobenzene, and several other compounds, in mixed acid and found the tritium to be replaced at the same rate as protium (table 6.1). Whilst the result shows only that the hydrogen is not appreciably loosened in the transition state of the rate-determining step, it is most easily understood in terms of the S 2 mechanism with... [Pg.110]

The picture of the process of substitution by the nitronium ion emerging from the facts discussed above is that of a two-stage process, the first step in which is rate-determining and which leads to a relatively stable intermediate. In the second step, which is relatively fast, the proton is lost. The transition state leading to the relatively stable intermediate is so constructed that in it the carbon-hydrogen bond which is finally broken is but little changed from its original condition. [Pg.112]

A primary isotope effect /ch/ d of 6.4 (extrapolated for 35 C) is observed for the metalation and the methylation of 171b when the C-5 position is deuterated. This value is in excellent agreement with the primary isotope effect of 6.6 reported for the metalation of thiophene (392) and it confirms that the rate-determining step is the abstraction by the base of the acidic proton. [Pg.124]

With the potential energies shown on a common scale we see that the transition state for formation of (CH3)3C is the highest energy point on the diagram A reaction can proceed no faster than its slowest step which is referred to as the rate determining step In the reaction of tert butyl alcohol with hydrogen chloride formation of the... [Pg.159]

As we have just seen the rate determining intermediate m the reaction of tert butyl alco hoi with hydrogen chloride is the carbocation (CH3)3C Convincing evidence from a variety of sources tells us that carbocations can exist but are relatively unstable When carbocations are involved m chemical reactions it is as reactive intermediates formed slowly m one step and consumed rapidly m the next one... [Pg.160]

The rate determining step m the S l mechanism is dissociation of the alkyloxo mum ion to the carbocation... [Pg.162]

Bromide ion forms a bond to the primary carbon by pushing off a water molecule This step IS bimolecular because it involves both bromide and heptyloxonium ion Step 2 IS slower than the proton transfer m step 1 so it is rate determining Using Ingold s ter mmology we classify nucleophilic substitutions that have a bimolecular rate determining step by the mechanistic symbol Sn2... [Pg.164]

Secondary and tertiary alcohols react with hydrogen halides by a mech anism that involves formation of a carbocation intermediate m the rate determining step... [Pg.179]

Primary alcohols do not react with hydrogen halides by way of carbo cation intermediates The nucleophilic species (Br for example) attacks the alkyloxonium ion and pushes off a water molecule from carbon m a bimolecular step This step is rate determining and the mechanism is Sn2... [Pg.181]

Assuming that the rate determining step in the reaction of cyclohexanol with hydrogen bro mide to give cyclohexyl bromide is unimolecular write an equation for this step Use curved arrows to show the flow of electrons... [Pg.185]

Like the reaction of tert butyl alcohol with hydrogen chloride step 2 m which tert butyloxonium ion dissociates to (CH3)3C and water is rate determining Because the rate determining step is ummolecular the overall dehydration process is referred to as a ummolecular elimination and given the symbol El... [Pg.206]

Because the rate determining step involves two molecules—the alkyloxonium ion and water—the overall reaction is classified as a bimolecular elimination and given the sym bol E2... [Pg.208]

What are the implications of the effects of the various halide leaving groups Because the halogen with the weakest bond to carbon reacts fastest Ingold concluded that the carbon-halogen bond breaks m the rate determining step The weaker the carbon-halogen bond the easier it breaks... [Pg.214]


See other pages where Rate determination is mentioned: [Pg.283]    [Pg.284]    [Pg.720]    [Pg.387]    [Pg.16]    [Pg.632]    [Pg.5]    [Pg.107]    [Pg.108]    [Pg.109]    [Pg.109]    [Pg.110]    [Pg.114]    [Pg.116]    [Pg.118]    [Pg.119]    [Pg.125]    [Pg.224]    [Pg.231]    [Pg.535]    [Pg.56]    [Pg.57]    [Pg.57]    [Pg.82]    [Pg.160]    [Pg.160]    [Pg.208]    [Pg.214]   
See also in sourсe #XX -- [ Pg.100 ]




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1,4-addition rate-determining step

Absolute rate constants, determination

Active Center Interconversions and the Determination of Absolute Rate Constants

Active center rate-determining

Adsorption or Desorption as the Rate-Determining Step

Adsorption rate determining

Aerobic rate determining step

Alkenes, addition reactions rate-determining step

Analyte recovery determination perfusion flow rate

And rate determining step

Annihilation rates determination

Applications rate determination

Atomic oxygen rate-determining formation

Average extension rate, determination

Basic Concepts in Chemical Kinetics—Determination of the Reaction Rate Expression

Bimolecular rate-determining step

Biotransformation rate determination

Bulk rate-determining step

Bulk rate-determining step pressure

Carbon monoxide rate determining steps

Carriers rate-determining adsorption

Catalytic rate constant determinants

Change in the rate-determining step

Chemical rate-determining step

Chemical reactions rate-determining step

Common Practices for Determining Relief Rates

Concept of Rate-Determining Step (rds)

Controlling rate factor, determination

Corrosion Rate Determination by Electrochemical Noise Analysis (ENA)

Corrosion rate determination chromium

Corrosion rate determination electrochemical methods

Corrosion rate determinations

Corrosion rate electrochemical determination

Cross-linking polymerization, rate, determining

Crystal growth rates, determination

Crystallization rate determination

Cuprous oxide rate determination

DETERMINING EXPERIMENTAL RATE EQUATIONS AT A FIXED TEMPERATURE

Decomposition, rate constant determination

Desorption of a product as the rate determining step

Desorption rate determining

Detachment, rate-determining step

Determination of Absolute Disintegration Rates

Determination of Absolute Rate Constants

Determination of Consumption Rates and Benthic Fluxes

Determination of Denitrification Rates

Determination of Elution Volumes and Flow Rates

Determination of Isothermal Crystallization Rate by DSC

Determination of Kinetic Rate Constants

Determination of Metabolic Rates and Enzyme Kinetics

Determination of Oxygen-Absorption Rate

Determination of Process Rates

Determination of Rate Equations for Single Reactions from Batch Reactor Data

Determination of Reaction Rate Expression

Determination of emission rate

Determination of propagation rate on free ions and ion-pairs in living polymerizations

Determination of rate

Determination of rate constant for

Determination of rate constants

Determination of reaction rate

Determination of relative rates

Determination of the Rate-Controlling Step

Determination of the Reaction Rate Expression

Determination of the individual rate constants

Determining rate parameters using quantum chemical calculations and transition state theory

Determining the Order and Rate Constant from Experimental Data

Determining the Rate Law by Experiment

Determining the optimum concentration rate

Diffusion rate determining step

Diffusion-based rate determination

Diffusion-controlled rate constant determination

Dipole rate-determining

Dissociation rate-determined model

Distribution rate constant determination

Effusion rates, vapor pressure determination

Electrochemical Corrosion-Rate Determination Techniques

Electrochemical Techniques for Determination of Corrosion Rate

Electrochemical rate-determining step

Electrode kinetics rate-determining step

Electron-impact dissociation, rate determination

Electrophilic addition rate-determining step

Elimination rate constant determination

Enzyme rate-determining step

Equations for the determination of rate orders

Evolution rates, experimental determination

Experimental Determination of Equilibrium Rate Constants

Experimental Determination of Rate

Experimental Determination of Reaction Order and Rate Constants

Experimental Methods for Determining Rate Laws

Experimental determination of rate constant

Experimental determinations of production rates

Experimental rate constant determination

FACTORS DETERMINING THE RATE OF A CHEMICAL REACTION

First-order rate constant determination

Floating-rate payments determination

Gelatin rate-determining step

General Reaction Kinetics Diffusion Resistance as the Rate-Determining Step

Global rates, determination

Growth Rate Determination

Haloform reaction rate determining step

Heterogeneous catalysis rate-determining step

Heterogeneous electron transfer rate constant determination

Heterogeneous reactions rate-determining step

Homogeneous or Heterogeneous Chemical Reaction as Rate-Determining Step

Homogeneous reactions rate-determining path

Homogeneous reactions rate-determining step

Hydroformylations rate-determining step

Hydrogenolysis rate determining step

INDEX rate-determination

Immobilization rate-determining step

Initial Rate Determination at Low Substrate

Integrated rate law reaction order, determining

Intercalation/deintercalation rate-determining process

Interest rates determination

Ionic compounds rate-determining step

Ionic reactions rate-determining step

Isomerization rate determining step

Kinase rate-determining step

Kinetics desorption rate determining

Kinetics rate-determining electron transfer

Kinetics rate-determining step

Kinetics, chemical rate-determining step

Mechanistic rate laws determination

Metabolic rate constant determination

Michaelis parameters determination from initial rate

Models rate-determining event

More on the Importance of a Rate-Determining Step

Multistep mechanisms rate-determining electron transfer

Nitrogen rate determining steps

Nucleophilic reactions rate-determining step

Nucleophilic substitution reactions rate-determining step

Oxidation rate determining step

Oxygen atoms, concentration determination rate constants

Oxygen rate-determining step

Oxygen transfer, rate-determining step

Partial reaction rate-determining

Pheromone release rate determination

Pitting corrosion rate-determining step

Polymer degradation, rate-determining

Potentiodynamic scan rate, determining

Potentiodynamic scan rate, determining pitting potentials

Pre Rate-Determining Steps

Precipitation kinetics, determination crystal growth rates

Precipitation kinetics, determination nucleation rates

Problem Determine the rate order of a reaction

Product analysis, rate constant determination

Product formation rate limiting step determination

Propagation rate constant, determination

Propane oxidation rate-determining step

Protein crystallization growth rate determination

Proton Transfer as the Rate-Determining Step

Proton dissociation rate determination

Proton transfer rate determining

Pseudo-order rate constants determination

Pseudo-steady state mode with a rate-determining step

Pure modes with interface rate determining step

Pyrolysis rate-determining step

Radical reactions, rate determination

Rate Determining Step and Steady-State Approximation

Rate Determining Step — Quasi-Equilibrium

Rate coefficient, definitions determination

Rate coefficients determination

Rate constant An experimentally determined

Rate constant determination

Rate constant determination for

Rate constant determination for curing isocyanate

Rate constant determination, differential method

Rate constant determination, integral method

Rate constant determining

Rate constant experimentally determining

Rate constant, proton dissociation determination

Rate constants potential-determining ions

Rate determining acyl halides

Rate determining amides

Rate determining carbonyl derivatives

Rate determining esters

Rate determining orthoesters

Rate determining parameter

Rate determining processes

Rate determining processes anisotropic etching

Rate determining processes anodic dissolution

Rate determining processes hydrogen termination

Rate determining processes metal deposition

Rate determining processes surface adsorption

Rate determining step

Rate determining step Stille coupling

Rate determining step acetal hydrolysis

Rate determining step amide hydrolysis

Rate determining step amines

Rate determining step approach

Rate determining step benzidine rearrangement

Rate determining step carboxylic esters with

Rate determining step compounds

Rate determining step during surface

Rate determining step during surface catalysis

Rate determining step in catalysis

Rate determining step interface

Rate determining step internal interface

Rate determining step methane

Rate determining step oxime formation

Rate determining step radical halogenation

Rate determining step, electrophilic aromatic

Rate determining step, electrophilic aromatic substitution

Rate determining step, in dissolution

Rate determining steps mechanism

Rate determining with acetylene

Rate determining with excited species

Rate equation experimental determination

Rate expression Determination

Rate expression, adsorption limiting determination

Rate expressions experimental determination

Rate factors determining

Rate law determination

Rate laws determining

Rate laws determining form

Rate, actual determining step

Rate, meaning determination

Rate-Determining Step in an ElcB Mechanism Aminolysis of Sulfamate Esters

Rate-Determining Steps of Reactions

Rate-concentration graphs, determination

Rate-determinating step

Rate-determined sensors

Rate-determining

Rate-determining Proton Transfer Processes

Rate-determining electron transfer, multistep

Rate-determining intermediate

Rate-determining intermediate transition state

Rate-determining mass transfer resistance

Rate-determining mechanism

Rate-determining multiple steps

Rate-determining oxidative cyclization

Rate-determining proton transfer steps

Rate-determining protonation

Rate-determining slow step

Rate-determining step , enzymatic

Rate-determining step Arrhenius plot

Rate-determining step The slowest

Rate-determining step activation energy

Rate-determining step bromination

Rate-determining step chain reactions

Rate-determining step change

Rate-determining step chlorination

Rate-determining step concept

Rate-determining step consecutive reactions

Rate-determining step crystal face

Rate-determining step electrophilic addition reactions

Rate-determining step importance

Rate-determining step in Haber process

Rate-determining step in electron-transfer processes

Rate-determining step in electrophilic aromatic substitution

Rate-determining step in substitution reactions

Rate-determining step of a reaction

Rate-determining step parallel reactions

Rate-determining step transfer coefficient

Rate-determining step, definition

Rate-determining step, definition 166 calculation

Rate-determining step, hydroformylation

Rate-determining step, pressure effects, high

Rate-determining step, reaction kinetics

Rate-determining steps molecularity

Rate-determining steps surface reactions

Rate-determining steps, in reactions

Rate-determining zone

Rate-determining/limiting step

Rate-determining/limiting step approximation

Rate-determining/limiting step change

Rates rate determining step

Reactants rate-determining step

Reaction mechanism rate-determining step

Reaction rate constant determination

Reaction rate determination

Reaction rate determined by a single step

Reaction rate determined by multiple steps

Reaction rate, determining

Reaction rates experimental determination

Reaction rates physical factors determining

Reaction rates rate-determining step

Reactions rate determining step

Reactivity of the rate-determining step

Reactivity of the rate-determining step in pure mode

Reactivity rate-determining step

Release rate determination

SN1 reactions rate-determining step

Second-order rate constant determination

Single rate-determining modes

Single rate-determining step

Site densities rate determining steps

Site densities, rate determining steps adsorption

Skill 9.8 Determining the rate law of a reaction from experimental data

Smith rate-determining step

Solvolytic reactions rate determination

Species and Rate-Determining Steps

Specific reaction-rate constant determination

Standard rate constant determination

Strand burning rate determination

Substitution, electrophilic rate determining step

Successive Electrode Reactions with One Rate-Determining Step

Surface rate-determining step

Surface rate-determining step pressure

Surface reaction as the rate determining step

Surface step rate-determining steps

Swap rates determinants

Swap rates determination

Systematic Determination of Reaction Mechanism and Rate Coefficients

Tafel polarization corrosion rate determination

Termination rate constant, determination

The Determination of Reaction Rates for Extremely Slow Reactions

The Determination of a Solvolysis Rate with Tritium Labeling

The Rate-Determining Step

The Rate-Determining Step for a Multistep Mechanism

The Rate-Determining Step of a Reaction Mechanism

The Stern-Volmer Equation for Determination of Quenching Rate

The rate-determining step approximation

Transition state Rate determining

Transition state theory, rate determining

Transition state theory, rate determining steps

Transition states rate-determining step

Transition-state theory unimolecular rate constant determination

Two rate-determining steps

Unimolecular rate-determining step

Urinary excretion rate determination

Using Initial Rates to Determine Rate Laws

WGSR rate-determining step

Waste determining leach rates

What Happens When One Rate-Determining Step Is Not Dominant

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