Kinetics and Mechanism of Oxidation of Tin(II) by Hexachloroiridate(IV) in Aqueous Perchlorate Solutions

1992 ◽  
Vol 57 (2) ◽  
pp. 326-331 ◽  
Author(s):  
Refat M. Hassan
Keyword(s):  
Reaction Mechanism ◽  
Reaction Rate ◽  
Activation Parameters ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Hydrogen Ion Concentration ◽  
First Order ◽  
Mechanism Of Oxidation ◽  
Kinetics Of ◽  
Overall Kinetics

The kinetics of hexachloroiridate(IV) oxidation of tin(II) in aqueous perchlorate media at a constant ionic strength of 2.0 mol dm-3 have been studied spectrophotometrically. The reaction was found to follow second-order overall kinetics and first order with respect to each of the reactants. The results showed hydrogen ion dependence where the reaction rate increased with increasing hydrogen ion concentration. The activation parameters were evaluated and a tentative reaction mechanism has been discussed.

Kinetics and Mechanism of Oxidation of Selenium(IV) by Permanganate Ion in Aqueous Perchlorate Solutions

1993 ◽  
Vol 58 (3) ◽  
pp. 538-546 ◽  
Author(s):  
Refat M. Hassan ◽  
Sahr A. El-Gaiar ◽  
Abd El-Hady M. El-Summan
Keyword(s):  
Reaction Mechanism ◽  
Reaction Rate ◽  
Oxidation Process ◽  
Selenium Dioxide ◽  
Order Reaction ◽  
Acid Solutions ◽  
First Order ◽  
Acid Catalyzed ◽  
Mechanism Of Oxidation ◽  
Kinetics Of

The kinetics of permanganate oxidation of selenium dioxide in perchloric acid solutions at a constant ionic strength of 2.0 mol dm-3 has been investigated spectrophotometrically. A first-order reaction in [MnO4-] and fractional order with respect to selenium(IV) were observed. The reaction rate was found to be pH-independent at lower acid concentrations ([H+] < 0.5 mol dm-3) and was acid-catalyzed beyond this range. Addition of Mn2+ and F- ions leads to the prediction that MnO4- is the sole reactive species in the oxidation process. A tentative reaction mechanism consistent with the reaction kinetics has been proposed.

The Formation of 3-Phenyl-2-thiohydantoins from Phenylthiocarbamyl Amino Acids

1963 ◽  
Vol 16 (3) ◽  
pp. 411 ◽  
Author(s):  
D Ilse ◽  
P Edman
Keyword(s):  
Amino Acids ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Hydrogen Ions ◽  
Hydrogen Ion Concentration ◽  
First Order ◽  
First Order Kinetics ◽  
Kinetics Of ◽  
Degradation Of Peptides

In an attempt to extend the application of the phenylisothiocyanate degradation of peptides it was found necessary to study the kinetics of the conversion of phenylthiocarbamyl amino acids into phenylthiohydantoins. The conversion was found to obey first-order kinetics and to be catalyzed by hydrogen ions. A set of conditions with regard to time, hydrogen ion concentration and temperature was found, which allowed the quantitative or near quantitative conversion of all phenylthiocarbamyl amino acids into phenylthiohydantoins with the only exception of the phenylthiohydantoin of serine, which was returned in a yield of 20%.

THE MECHANISM OF THE ALCOHOLYSIS OF ALIPHATIC NITRITES: II. ACID-CATALYZED ALCOHOLYSIS OF 1-METHYLHEPTYL NITRITE

1961 ◽  
Vol 39 (4) ◽  
pp. 947-953 ◽  
Author(s):  
A. D. Allen ◽  
G. R. Schonbaum
Keyword(s):  
Reaction Rate ◽  
Chloride Ion ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Lithium Salts ◽  
Hydrogen Ion Concentration ◽  
First Order ◽  
Low Concentrations ◽  
Acid Catalyzed ◽  
Asymmetric Carbon

The acid-catalyzed alcoholysis of 1-methylheptyl nitrite has been studied kinetically. The reaction rate is first order with respect to both the nitrite and the hydrogen ion concentration, and the reaction does not involve the asymmetric carbon center. Addition of lithium salts (chloride and perchlorate) indicates catalysis by chloride ion. Addition of water in low concentrations inhibits the reaction strongly. These results and the mechanism of the reactions are discussed in terms of the properties of the alcohols and the dissociation of the acid catalysts in the alcohols used.

Kinetics of the oxidation of Pu(IV) by manganese dioxide

2002 ◽  
Vol 90 (2) ◽  
Author(s):  
A. Morgenstern ◽  
Gregory R. Choppin
Keyword(s):  
Manganese Dioxide ◽  
Rate Equation ◽  
Oxidation Reaction ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Hydrogen Ion Concentration ◽  
First Order ◽  
Order Dependence ◽  
Ph Range ◽  
Kinetics Of

SummaryThe kinetics of the oxidation of plutonium(IV) by manganese dioxide were studied in 1.0 M NaCl over the pH range from 2.5 to 8.2 with variable concentrations of manganese dioxide from 0.01 mIn the pH range from 2.0 to 3.5, the oxidation of Pu(IV) by manganese dioxide was first order with respect to the concentration of manganese dioxide and −0.21 with respect to the hydrogen ion concentration. Consequently, assuming a first order dependence with respect to the concentration of Pu(IV), the oxidation reaction can be described by the following rate equation:with

scholarly journals ANOMALIES IN THE ABSORPTION SPECTRUM AND BLEACHING KINETICS OF VISUAL PURPLE

1936 ◽  
Vol 19 (4) ◽  
pp. 577-599 ◽  
Author(s):  
Aurin M. Chase
Keyword(s):  
Seasonal Variation ◽  
Order Equation ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Seasonal Effect ◽  
Hydrogen Ion Concentration ◽  
Winter Condition ◽  
First Order ◽  
Summer Condition ◽  
Kinetics Of

Visual purple from winter frogs shows an intermediate yellow color during bleaching by light; summer extractions do not. This seasonal effect can be duplicated by variations in the hydrogen ion concentration and in the temperature of the solutions. Increasing the pH approximates the summer condition, while decreasing the pH approximates the winter condition. Temperature has no effect on the bleaching of alkaline solutions but greatly influences acid solutions. At low temperatures the bleaching of add solutions resembles the winter condition, while at higher temperatures it resembles the summer condition. A photic decomposition product of frog retinal extractions is an acid-base indicator: it is yellow in acid and colorless in alkaline solution. Its color is not dependent upon light. The hydrogen ion concentration of visual purple solutions does not change under illumination, nor is there a difference in the pH of summer and winter extractions. Bile salt extractions of visual purple are usually slightly acid. The conflicting results of past workers regarding the appearance of "visual yellow" may be due to seasonal variation with its differences in temperature, or to the presence of base in the extractions. It is also possible that vitamin A may be a factor in the seasonal variation. The photic decomposition of visual purple in bile salts solution, extracted from summer frogs, follows the kinetics of a first order reaction. Visual purple from winter frogs does not conform to first order kinetics. Photic decomposition of alkaline, winter visual purple extractions also follows a first order equation. Acid, winter extractions appear to conform to a second order equation, but this is probably an artefact due to interference by the intermediate yellow.

THE MONO-OXALATO COMPLEXES OF IRON(III): PART II. KINETICS OF FORMATION

1965 ◽  
Vol 43 (10) ◽  
pp. 2763-2771 ◽  
Author(s):  
R. F. Bauer ◽  
W. MacF. Smith
Keyword(s):  
Rate Constant ◽  
Order Rate Constant ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Experimental Conditions ◽  
Hydrogen Ion Concentration ◽  
First Order ◽  
Independent Path ◽  
Kinetics Of ◽  
Oxalato Complexes

The kinetics of the formation of the mono-oxalato complexes of iron (III) have been examined spectrophotometrically over the range of temperatures 5 to 25 °C in an aqueous medium of ionic strength 0.50 and the range of hydrogen ion concentrations 0.03 to 0.45 M. The kinetic-ally significant paths under the conditions studied involve reactions first order in iron (III) and in bioxalate but there appears to be some decrease in the second order rate constant with increase in hydrogen ion concentration at the highest acidities and at the highest temperatures. Although there is no significant contribution to the rate by an acid-independent path first order in free oxalate under the experimental conditions, the possibility of the rate constant for such a path being greater than that first order in bioxalate is not precluded.

scholarly journals Reactivity of Phenol and Aniline towards Quinolinium Chloro Chromate: A Comparative Oxidation Kinetic Study

2015 ◽  
Vol 59 ◽  
pp. 81-92
Author(s):  
Seplapatty Kalimuthu Periyasamy ◽  
H. Satham Hussain ◽  
R. Manikandan
Keyword(s):  
Oxidation Kinetic ◽  
Activation Parameters ◽  
Dipole Interaction ◽  
Reaction Rates ◽  
Hydrogen Ion ◽  
Aqueous Acetic Acid ◽  
Acetic Acid Medium ◽  
First Order ◽  
Different Temperatures ◽  
Kinetics Of

The kinetics of Oxidation of Phenol and aniline by quinolinium Chlorochromate (QCC) in aqueous acetic acid medium leads to the formation of quinone and azobenzene respectively. The reactions are first order with respect to both Phenol and aniline. The reaction is first order with respect to quinolinium chlorochromate (QCC) and is catalyzed by hydrogen ion. The hydrogen-ion dependence has the form: kobs = a+b [H+]. The rate of oxidation decreases with increasing dielectric constant of solvent, indicating the presence of an ion-dipole interaction. The reaction does not induced the polymerization of acrylonitrile. The retardation of the rate by the addition of Mn2+ ions confirms that a two electron transfer process is involved in the reaction. The reaction rates have been determined at different temperatures and the activation parameters have been calculated. From the above observations kinetic results a probable mechanism have been proposed.

Mechanistic Information from the Effect of Pressure on the Kinetics of Hydrolysis of Iodopentaaquochromium(III) Ion

1975 ◽  
Vol 53 (24) ◽  
pp. 3697-3701 ◽  
Author(s):  
Milton Cornelius Weekes ◽  
Thomas Wilson Swaddle
Keyword(s):  
Ionic Strength ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Hydrogen Ion Concentration ◽  
Kinetics Of Hydrolysis ◽  
Rate Of Hydrolysis ◽  
Kinetics Of ◽  
Hydrolysis Of ◽  
Aqueous Hclo ◽  
Conjugate Base

The rate of hydrolysis of iodopentaaquochromium(III) ion has been measured as a function of pressure (0.1 to 250 MPa) and hydrogen ion concentration (0.1 to 1.0 mol kg−1) at 298.2 K and ionic strength 1.0 mol kg−1 (aqueous HClO4–LiClO4). The volumes of activation for the acid independent and inversely acid dependent hydrolysis pathways are −5.4 ± 0.5 and −1.6 ± 0.3 cm3 mol−1 respectively, and are not detectably pressure-dependent. Consideration of these values, together with the molar volume change of −3.3 ± 0.3 cm3 mol−1 determined dilatometrically for the completed hydrolysis reaction, indicates that the mechanisms of the two pathways are associative interchange (Ia) and dissociative conjugate base (Dcb) respectively.

scholarly journals KINETICS OF LYSIS BY CLOSTRIDIUM SEPTICUM HEMOLYSIN

1944 ◽  
Vol 80 (4) ◽  
pp. 333-339 ◽  
Author(s):  
Alan W. Bernheimer
Keyword(s):  
Hydrogen Ion ◽  
Ion Concentration ◽  
Clostridium Septicum ◽  
Ph Optimum ◽  
Hydrogen Ion Concentration ◽  
Catalyzed Reactions ◽  
Enzyme Catalyzed Reactions ◽  
Kinetics Of

The kinetics of the hemolytic reaction effected by the hemolysin of Clostridium septicum, strain 44, has been studied with regard to the effect of concentration, temperature, and hydrogen ion concentration on the rate of the hemolytic reaction. The kinetics of hemolysis was found to resemble in several respects that of enzyme-catalyzed reactions, but differed in the absence of a clearly defined pH optimum. Attention is drawn to differences between the hemolytic system studied and certain other hemolytic systems.

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.

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