Kinetics and Mechanism of Redox Reaction between Tetrachloroaurate(III) Ions and Hydrazine

2014 ◽  
Vol 46 (6) ◽  
pp. 328-337 ◽  
Author(s):  
Bartłomiej Streszewski ◽  
Wiktor Jaworski ◽  
Konrad Szaciłowski ◽  
Krzysztof Pacławski
Keyword(s):  
Redox Reaction ◽  
Kinetics And Mechanism

Kinetics and mechanism of the reduction of CrVI to CrIII by D-ribose and 2-deoxy-D-ribose

1999 ◽  
Vol 77 (1) ◽  
pp. 57-64 ◽  
Author(s):  
Verónica Daier ◽  
Sandra Signorella ◽  
Marcela Rizzotto ◽  
María Inés Frascaroli ◽  
Claudia Palopoli ◽  
...  
Keyword(s):  
Redox Reaction ◽  
Kinetics And Mechanism ◽  
Epr Spectra ◽  
Oxidation Reactions ◽  
Redox Mechanism ◽  
Rate Laws ◽  
Aldonic Acid

The oxidation of D-ribose and 2-deoxy-D-ribose by CrVI yields the aldonic acid and Cr3+ as final products when an excess of sugar over CrVI is used. The redox reaction occurs through CrVI–>CrIII and CrVI–>CrV–>CrIII paths. The complete rate laws for the CrVI oxidation reactions are expressed by -d[CrVI]/dt = kH[H+]2 [ribose][CrVI], where kH = (5.9 ± 0.1) × 10-2 mol-3 dm9 s-1, and -d[CrVI]/dt = (k0 + kH'[H+]2) [2-deoxyribose][CrVI], where k0 = (1.3 ± 0.5) × 10-3 mol-1 dm3 s-1 and kH' = (4.2 ± 0.1) × 10-2 mol-3 dm9 s-1, at 33°C. An intermediate sugar alkoxide radical could be trapped with DMPO and observed by EPR as a multiline signal at g = 2.003. CrV is formed in a rapid step by reaction of the sugar radical with CrVI. CrV reacts with the substrate faster than CrVI does. The EPR spectra show that five- and six-coordinate oxochromate(V) intermediates are formed, and the distribution of these CrV species in the reaction mixture essentially depends on the solution acidity.Key words: ribose, 2-deoxyribose, chromium, redox, mechanism, kinetics.

Redox reaction of 1,2-dihydroxybenzene with Mn(III) in aqueous perchlorate media. Kinetics and mechanism

1975 ◽  
Vol 12 (1) ◽  
pp. 61-65 ◽  
Author(s):  
E. Mentasti ◽  
E. Pelizzetti ◽  
E. Pramauro ◽  
G. Giraudi
Keyword(s):  
Redox Reaction ◽  
Kinetics And Mechanism

scholarly journals Kinetics and Mechanism of the Redox Reaction Between Pt(IV) Complex Ions and Sodium Thiosulfate in Aqueous Solution. Part II: Neutral and Alkaline Solution/ Kinetyka I Mechanizm Reakcji Redoks Pomiędzy Jonami Kompleksowymi Pt(Iv) I Tiosiarczanem Sodu W Roztworze Wodnym. Część II: Roztwór Obojętny I Zasadowy

2014 ◽  
Vol 59 (4) ◽  
pp. 1421-1426
Author(s):  
K. Pacławski ◽  
J. Piwowonska
Keyword(s):  
Rate Constant ◽  
Redox Reaction ◽  
Sodium Thiosulfate ◽  
Order Rate Constant ◽  
Reduction Reaction ◽  
Kinetics And Mechanism ◽  
Complex Ions ◽  
Entropy Of Activation ◽  
Enthalpy And Entropy ◽  
Mechanism Of The Reaction

Abstract In this work, spectrophotometric studies on the kinetics and mechanism of the reaction between [PtCl6]2- complex ions and sodium thiosulfate, in neutral (pH = 7) and alkaline (p = 12) solution, were carried out. Applying different conditions, the influence of initial concentrations of reductant and platinum(IV) complex ions as well as the influence of temperature and ionic strength on the rate constant, was experimentally determined. From the obtained results, the molecularity, the order and the value of enthalpy and entropy of activation of the reaction, were experimentally determined. It was found that in both cases the reduction reaction is relatively slow and in the studied conditions the second-order rate constant changes from 2.92 : 10-2 to 0.40 M-1:s-1 at pH = 7, and from 3.84 : 10-2 to 1.55 M-1s-1 at pH = 12. Additionally, depending on the pH, different mechanism of the reaction is present. However, regardless on the studied system the only platinum(II) chloride complex ions are the final product of the redox reaction.

Kinetics and mechanism of the redox reaction of thallic sulphate with acroleine

1980 ◽  
Vol 45 (4) ◽  
pp. 1173-1181 ◽  
Author(s):  
Ľudovít Treindl ◽  
Milan Melicherčík
Keyword(s):  
Sulphuric Acid ◽  
Rate Equation ◽  
Redox Reaction ◽  
Reaction Order ◽  
Kinetics And Mechanism ◽  
Aqueous Dioxane ◽  
Rate Determining Step

The stoichiometry, kinetics and mechanism of the redox reaction of thallic sulphate with acroleine in aqueous sulphuric acid or in aqueous dioxane solutions were studied. The acroleine molecule is oxidised with Tl(III) ions in two consecutive one-electron steps to glyceraldehyde. The corresponding rate equation is -d[Tl(III)]/dt = k[Tl(III)]n [A], where n = 0-2. The zeroth reaction order with respect to thallic ions is attributed to a slow enolization of the hydrated acroleine, which is the rate-determining step preceding the redox reaction proper.

Sign in / Sign up

Export Citation Format

Share Document