Kinetics and Mechanism of the Chromium(VI) Oxidation of Formic Acid in the Presence of Picolinic Acid and in the Presence and Absence of Surfactants
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Asim K. Das
Abstract
The kinetics and mechanism of picolinic acid (PA)- catalysed oxidation of formic acid have been studied in aqueous HClO4 media under the experimental conditions, 103[Cr(VI)]T = 0.67-2.67 mol dm-3, [PA]T = 0.01-0.12 mol dm-3, [HCO2H]T = 0.1-0.8 mol dm-3, [H+] = 0.35-1.5 mol dm-3,1 = 1.5 mol dm-3 in the temperature range 25-40° C. The kinetic parameters of the catalysed path have been compared with those of the relatively slower uncatalysed path which proceed parallelly with the catalysed path. In the catalysed path, Cr(VI)-PA cyclic complex formed at the pre-equilibrium step receives a nucleophilic attack at the Cr(VI) centre by the substrate leading to a ternary complex with the release of a proton in a reversible path. Then the ternary complex experiences the redox decomposition at the rate-determining step giving rise to Cr(IV)-PA complex and CO2. Then the Cr(IV)-PA complex reacts faster ultimately giving rise to Cr(III)-PA complex. The anionic surfactant sodium dodecyl sulfate (SDS) catalyses both the uncatalysed and catalysed paths in aqueous HClO4 media while the cationic surfactant cetyl pyridinium chloride (CPC) inhibits the reactions in aqueous H2SO4 media. In the presence of the surfactants, applicability of the Piszkiewicz model has been tested for the ΡΑ-catalysed path. Micellar effects are in conformity with the proposed mechanism.
© 2014 by Walter de Gruyter Berlin/Boston
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- The Dependence of the Copper Dissociation Rate Constants from Human(Serum)- and Ονο-Transferrin on pH and the Anions
- Kinetics of the Photosubstitution of ds-Bis(benzonitrile)dichloroplatinum(II) in Chloroform
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- Kinetics and Mechanism of Oxidation of Tellurium(IV) by Alkaline Diperiodatonickelate(IV)
- Complexation of Pendant Arm Macrocycles with Cu(II) Hydroxo Complexes in Strongly Alkaline Solutions. Investigation of pH Dependences
- Kinetics and Mechanism of the Chromium(VI) Oxidation of Formic Acid in the Presence of Picolinic Acid and in the Presence and Absence of Surfactants
- Kinetics and Mechanism of Chromium(III) Catalysed Oxidation of Propan-1-ol and Butan-1-ol by Cerium(IV) in Aqueous Sulfuric acid Media
- Notes for Contributors. Inorganic Reaction Mechanisms
- Journal Order Form
Articles in the same Issue
- Tribute
- Kinetics of Dissociation of the Cobalt(II) and Copper(II) Complexes of 2,2′,2″-tris(monomethylamino)triethylamine in Aqueous Acidic Solution
- The Influence of Steric Effects on the Oxidation Kinetics of [FeII(aminopolycarboxylato)] Complexes with Dioxygen
- The Hydrolysis Kinetics of ds-diamminedichloroplatinum(II). 10. Activation Volumes for Halide Anation of Some czs-[Pt(N)2(OH2)2]2+ Systems
- The Dependence of the Copper Dissociation Rate Constants from Human(Serum)- and Ονο-Transferrin on pH and the Anions
- Kinetics of the Photosubstitution of ds-Bis(benzonitrile)dichloroplatinum(II) in Chloroform
- Kinetics and Mechanisms of the Reaction of Aluminium(III) with Polyaminocarboxylic Acids
- Kinetics and Mechanism of Oxidation of Tellurium(IV) by Alkaline Diperiodatonickelate(IV)
- Complexation of Pendant Arm Macrocycles with Cu(II) Hydroxo Complexes in Strongly Alkaline Solutions. Investigation of pH Dependences
- Kinetics and Mechanism of the Chromium(VI) Oxidation of Formic Acid in the Presence of Picolinic Acid and in the Presence and Absence of Surfactants
- Kinetics and Mechanism of Chromium(III) Catalysed Oxidation of Propan-1-ol and Butan-1-ol by Cerium(IV) in Aqueous Sulfuric acid Media
- Notes for Contributors. Inorganic Reaction Mechanisms
- Journal Order Form
