scholarly journals KINETICS OF REACTION BETWEEN MALACHITE GREEN AND HYDROXYL ION IN THE PRESENCE OF REDUCING SUGARS

2015 ◽  
Vol 23 (23) ◽  
pp. 61-72
Author(s):  
Dayo Felix Latona ◽  
Adewumi Oluwasogo Dada
Keyword(s):  
Malachite Green ◽  
Activation Parameters ◽  
Cell Compartment ◽  
First Order ◽  
Rate Determining Step ◽  
First Order Kinetics ◽  
Hydroxyl Ion ◽  
Kinetics Of Reaction ◽  
Kinetics Of ◽  
Sphere Mechanism

The reaction was studied via pseudo-first-order kinetics using a UV-1800 Shimadzu spectrophotometer with a thermostated cell compartment and interfaced with a computer. The reaction showed first order with respect to malachite green and sugar and hydroxyl ion concentrations. However, the reaction was independent of ionic strength and showed no dependence on the salt effect, indicating an inner sphere mechanism for the reaction. There was no polymerization of the reaction mixture with acrylonitrile, indicating the absence of radicals in the course of the reaction. Michaelis-Menten plot indicated the presence of a reaction intermediate in the rate-determining step. The activation parameters of the reaction have been calculated and products were elucidated by FTIR spectroscopy. The stoichiometry of the reaction is 1:1. A mechanism consistent with the above facts has been suggested.

The kinetics and the mechanism of oxidative decarboxylation of benzilic acid by acidic permanganate (stopped-flow technique) — An autocatalytic study

2004 ◽  
Vol 82 (9) ◽  
pp. 1372-1380 ◽  
Author(s):  
Sairabanu A Farokhi ◽  
Sharanappa T Nandibewoor
Keyword(s):  
Activation Parameters ◽  
Oxidative Decarboxylation ◽  
Two Stage ◽  
First Order ◽  
First Order Kinetics ◽  
Stage Process ◽  
Benzilic Acid ◽  
Reaction Constants ◽  
Kinetics Of ◽  
Good Agreement

The kinetics of the oxidation of benzilic acid by potassium permanganate in an acidic medium were studied spectrophotometrically. The reaction followed a two-stage process, wherein both stages of the reaction followed first-order kinetics with respect to permanganate ion and benzilic acid. The rate of the reaction increased with an increase in acid concentration. Autocatalysis was observed by one of the products, i.e., manganese(II). A composite mechanism involving autocatalysis has been proposed. The activation parameters of the reaction were calculated and discussed and the reaction constants involved in the mechanisms were calculated. There is a good agreement between the observed and calculated rate constants under different experimental conditions.Key words: oxidation, autocatalysis, benzilic acid, two-stage kinetics.

scholarly journals Kinetics and Mechanism of Oxidation of Diethanolamine and Triethanolamine by Potassium Ferrate

2011 ◽  
Vol 8 (2) ◽  
pp. 903-909 ◽  
Author(s):  
Shan Jinhuan ◽  
Zhang Jiying
Keyword(s):  
Activation Parameters ◽  
Rate Equations ◽  
Potassium Ferrate ◽  
Kinetics Of Oxidation ◽  
First Order ◽  
Order Dependence ◽  
Rate Determining Step ◽  
Thermodynamic Activation Parameters ◽  
Plausible Mechanism ◽  
Kinetics Of

The kinetics of oxidation of diethanolamine and triethanolamine by potassium ferrate(VI)in alkaline liquids at a constant ionic strength has been studied spectrophotometrically in the temperature range of 278.2K-293.2K. The reaction shows first order dependence on potassium ferrate(VI), first order dependence on each reductant, The observed rate constant (kobs) decreases with the increase in [OH-], the reaction is negative fraction order with respect to [OH-]. A plausible mechanism is proposed and the rate equations derived from the mechanism can explain all the experimental results. The rate constants of the rate-determining step and the thermodynamic activation parameters are calculated.

Kinetics of the Substitution of Norbornadiene in Tetracarbonyl(norbomadiene)molybdenum(0) by 2,2'-Bipyridine

2001 ◽  
Vol 56 (3) ◽  
pp. 281-286 ◽  
Author(s):  
Ceyhan Kayran ◽  
Eser Okan
Keyword(s):  
Reaction Rate ◽  
Activation Parameters ◽  
Bipy Ligand ◽  
First Order ◽  
Rate Determining Step ◽  
Vis Spectroscopy ◽  
Different Temperatures ◽  
Ft Ir ◽  
Thermal Substitution ◽  
Kinetics Of

Abstract The kinetics of the thermal substitution of norbornadiene (nbd) by 2,2'-bipyridine (2,2'-bipy) in (CO)4Mo(C7H9) was studied by quantitative FT-IR and UV-VIS spectroscopy. The reaction rate exhibits first-order dependence on the concentration of the starting complex, and the observed rate constant depends on the concentration of both leaving nbd and entering 2,2'-bipy ligand. The mechanism was found to be consistent with the previously proposed one, where the rate determining step is the cleavage of one of the two Mo-olefin bonds. The reaction was performed at four different temperatures (35 -50 °C) and the evaluation of the kinetic data gives the activation parameters which now support states.

Die Stärke von optokinetischen Reaktionen auf verschiedene Mustergeschwindigkeiten

1958 ◽  
Vol 13 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Bernhard Hassenstein
Keyword(s):  
Angular Velocity ◽  
Stimulus Situation ◽  
Stripe Pattern ◽  
First Order ◽  
First Order Kinetics ◽  
Light Stimuli ◽  
Mathematical Evaluation ◽  
Kinetics Of Reaction ◽  
Kinetics Of ◽  
Logarithmic Relation

The strength of optokinetic reactions in the beetle Chlorophanus has been measured in relation to the angular velocity of a moving irregular stripe pattern (Fig. 2). The stimulus situation was so arranged that only one type of elementary perception mechanism was involved. As shown in Fig. 4 the reactions followed very well REICHARDT'S theoretical curve (5, Fig. 9), which was calculated from experiments on the interaction between single successive light stimuli in the eye (cf. the CNS) of Chlorophanus. Mathematical evaluation of the experimental facts shows that the two types (E and D 3, 5) of transmitting elements involved possess linear first order kinetics of reaction. The time constants of the E- and D-Elements proved to have the value of 3,5 sec and 46 msec, making a quotient of 76,24. These figures determine a nearly logarithmic relation between angular velocity and strength of reaction within the range from 2°/sec to 40°/sec, a maximum of reaction near 50°/sec and a logarithmic decrease from 100°/sec to 2000°/sec (see Fig. 4). - The experimental results confirmed, that the movement perception of the beetle Chlorophanus works in accordance with the principle of autocorrelation.

Kinetics of the Oxidation of Aliphatic Aldehydes by Chromic Acid

1971 ◽  
Vol 26 (5) ◽  
pp. 383-385 ◽  
Author(s):  
C. Goswami ◽  
K. K. Banerji
Keyword(s):  
Acetic Acid ◽  
Chromic Acid ◽  
Activation Parameters ◽  
Acid Oxidation ◽  
First Order ◽  
Chromic Acid Oxidation ◽  
Rate Determining Step ◽  
Reversible Formation ◽  
Kinetics Of ◽  
Chromate Ion

The kinetics of chromic acid oxidation of propanaldehyde, butyraldehyde and isobutyraldehyde in aq. acetic acid have been studied. The product of the oxidation is the corresponding carboxylic acid. The reaction is of first order with respect to each the acid chromate ion, HCrO4⊖, and the aldehyde but of second order to hydrogen ion. The rate increases with proportion of acetic acid in the solution. The activation parameters for the oxidation and enolisation reactions have been evaluated. The rate of enolisation under similar condition is less than that of oxidation. A mechanism in which the first step is the rapid reversible formation of a chromate ester followed by a hydrideion transfer in the rate determining step has been suggested.

THE KINETICS OF REACTION OF 2,2-DIPHENYL-1-PICRYLHYDRAZYL WITH PHENOLS

1961 ◽  
Vol 39 (8) ◽  
pp. 1588-1594 ◽  
Author(s):  
J. S. Hogg ◽  
D. H. Lohmann ◽  
K. E. Russell
Keyword(s):  
Hydrogen Atom ◽  
Steric Hindrance ◽  
Hydrogen Abstraction ◽  
Phenoxy Radical ◽  
First Order ◽  
Rate Determining Step ◽  
Kinetics Of Reaction ◽  
Kinetics Of

The kinetics of reaction between 2,2-diphenyl-1-picrylhydrazyl (DPPH) and a wide variety of phenols have been studied. The rate of disappearance of DPPH is of first order with respect to both the DPPH and the reacting phenol. The rates of reaction can be roughly correlated with the Hammett σ value of the phenol substituent in the range −0.4 < σ < 0.2, a ρ value of −6 being obtained. t-Butyl groups in both ortho positions of the phenol give rise to steric hindrance, the reduction in rate being largely due to a reduction in the A factor. Hydrogen abstraction from the less reactive phenols is strongly retarded by the product, 2,2-diphenyl-1-picrylhydrazine.The rate-determining step probably involves the abstraction of a hydrogen atom from the phenol by the DPPH to give diphenylpicrylhydrazine and a phenoxy radical. The retardation by diphenylpicrylhydrazine is readily explained if this primary step is reversible.

scholarly journals Kinetics and mechanism of the oxidation of polyhydric alcohols by dihydroxyditelluratoargentate(III) in alkaline medium

2005 ◽  
Vol 70 (4) ◽  
pp. 585-592 ◽  
Author(s):  
J.H. Shan ◽  
S.Y. Huo ◽  
S.G. Shen ◽  
H.W. Sun
Keyword(s):  
Alkaline Medium ◽  
Activation Parameters ◽  
Order Rate Constant ◽  
Active Species ◽  
Rate Equations ◽  
Kinetics Of Oxidation ◽  
First Order ◽  
Rate Determining Step ◽  
Plausible Mechanism ◽  
Kinetics Of

The kinetics of oxidation of 1,2-propanediol and 1,2,3-propanetriol by dihydroxyditelluratoargentate(III) (DDA) were studied spectrophotometrically between 298.2 K and 313.2 K in alkaline medium. The reaction rate showed first order dependence on DDA and 1 < nap < 2 order on the reductant. It was found that the pseudo-first order rate constant kobs increased with increasing concentration of OH-1 and decreasing concentration of TeO42-. There is a negative salt effect and no free radicals were detected. In view of this, the dihydroxymonotelluratoargentate(III) species is assumed to be the active species. A plausible mechanism involving a two-electron transfer is proposed and the rate equations derived from the mechanism can explain all the experimental results. The activation parameters, as well as the rate constants of the rate-determining step were calculated.

scholarly journals Kinetics of Oxidation of Benzoin by N. Bromosuccinimide

2005 ◽  
Vol 4 (1) ◽  
pp. 55-61
Author(s):  
R. Sridharan ◽  
N. Mathiyalagan
Keyword(s):  
Dielectric Constant ◽  
Acetic Acid ◽  
Reaction Rate ◽  
Activation Parameters ◽  
Aqueous Acetic Acid ◽  
Kinetics Of Oxidation ◽  
First Order ◽  
First Order Kinetics ◽  
Retarding Effect ◽  
Kinetics Of

Kinetics of Oxidation of Benzoin by N. Bromosuccinimide[NBS] 80% aqueous acetic acid has been investigated. The reaction follows first-order kinetics with respect to both[NBS] and [benzoin]. The effect of varying ionic strength and dielectric constant indicate the reaction is dipole-dipole type. Addition of succinimide(>NH), has a retarding effect on the rate of oxidation. The product of oxidation is benzil. By studying the effect of temparature on the reaction rate, the Arrhenius and the activation parameters have been calculated. A suitable mechanism has been proposed and a rate low explaining the experiment results is derived.

scholarly journals Kinetics and Mechanism of Oxidation of Isobutylamine and 1,4-Butanediamine by Potassium Ferrate

2011 ◽  
Vol 8 (3) ◽  
pp. 1371-1377
Author(s):  
Shan Jinhuan ◽  
Yang Yafeng
Keyword(s):  
Activation Parameters ◽  
Rate Equations ◽  
Potassium Ferrate ◽  
Kinetics Of Oxidation ◽  
First Order ◽  
Rate Determining Step ◽  
Thermodynamic Activation Parameters ◽  
Plausible Mechanism ◽  
Mechanism Of Oxidation ◽  
Kinetics Of

The kinetics of oxidation of isobutylamine and 1,4-butanediamine by home-made potassium ferrate(VI) at different conditions has been studied spectrophotometrically in the temperature range of 288.2 -303.2 K. The results show first order dependence on potassium ferrate(VI) and on each reductant. The observed rate constant (kobs) decreases with the increase of [OH-], the reaction was negative fraction order with respect to [OH-]. A plausible mechanism was proposed and the rate equations derived from the mechanism can explain all the experimental results. The rate constants of the rate-determining step and the thermodynamic activation parameters were calculated.

Kinetics of the acid-catalysed hydration of prop-2-en-1-ol. Evidence for a free, ion-dipole intermediate in the heterolysis of propane-1,2-diol

1982 ◽  
Vol 35 (11) ◽  
pp. 2221 ◽  
Author(s):  
KP Herlihy
Keyword(s):  
Activation Parameters ◽  
Optically Active ◽  
First Order ◽  
Aqueous Acid ◽  
First Order Kinetics ◽  
Pinacol Rearrangement ◽  
Free Ion ◽  
Pseudo First Order ◽  
Kinetics Of ◽  
Good Agreement

Prop-2-en-1-ol in aqueous acid solution gives propane-1,2-diol and propanal. At 100�C the amount of diol in this product ratio is found to decrease from 65% in 1 M HClO4 to 50% in 4 M HClO4. Pseudo-first-order kinetics are found to apply. The values obtained for the activation parameters, Ea and ΔS‡ and for a Hammett acidity plot, are similar to results reported for other alkenes. The relative rates of partitioning between regeneration of the substrate and rearrangement for the pinacol rearrangement of optically active propane-1,2-diol have been calculated previously. When these are compared with product ratios obtained from the hydration of prop-2-en-1-ol, good agreement is found between the respective values if it is assumed that the regenerated substrate has undergone complete racemization of configuration. This is interpreted to be evidence for a short-lived, but free ion-dipole as the intermediate in the heterolysis of propane-1,2-diol.

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