✦ LIBER ✦

A kinetic study of the oxidation of L-ascorbic acid by chromium(VI)

✍ Scribed by Joaquin F. Perez-Benito; Conchita Arias

Publisher: John Wiley and Sons
Year: 1993
Tongue: English
Weight: 341 KB
Volume: 25
Category: Article
ISSN: 0538-8066
DOI: 10.1002/kin.550250402

No coin nor oath required. For personal study only.

✦ Synopsis

The reaction between chromium(V1) and L-ascorbic acid has been studied by spectrophotometry in the presence of aqueous citrate buffers in the pH range 5.69-7.21. The reaction is slowed down by an increase of the ionic strength. At constant ionic strength, manganese(I1) ion does not exert any appreciable inhibition effect on the reaction rate. The rate law found is

where K , is the equilibrium constant for protonation of chromate ion and k, is the rate constant for the redox reaction between the active forms of the oxidant (hydrogenchromate ion) and the reductant (L-hydrogenascorbate ion). The activation parameters associated with rate constant k , are E, = 20.4 t 0.9 kJ mol-', AH' = 17.9 2 0.9 kJ mol-', and AS' = -152 2 3 J K-' moll . The reaction thermodynamic magnitudes associated with equilibrium constant K , are AHo = 16.5 2 1.1 kJ mol-' and ASo = 167 2 4 J K-' mol-'. A mechanism in accordance with the experimental data is proposed for the reaction.

📜 SIMILAR VOLUMES

Kinetic studies on the oxidation of asco

Kinetic studies on the oxidation of ascorbic acid by technetium(VII)

✍ F. Grases; C. Genestar; E. Amat 📂 Article 📅 1986 🏛 John Wiley and Sons 🌐 English ⚖ 297 KB 👁 1 views

The pertechnetate ion oxidizes ascorbic acid in strong acid medium to form red species. A reaction mechanism has been developed which correctly predicts all the experimental facts. The results obtained support the postulate according to which the red species corresponds to a complex formed between T

Kinetic study of the oxidation of ethano

Kinetic study of the oxidation of ethanol by 3,4-lutidine chromium(VI) peroxide in dichloromethane solution

✍ Mir Fazlollah Mousavi; Habib Firouzabadi; Mojtaba Shamsipur 📂 Article 📅 1994 🏛 John Wiley and Sons 🌐 English ⚖ 300 KB 👁 1 views

## Abstract The oxidation kinetics of ethanol with 3,4‐lutindine chromium(VI) peroxide (LCP) were investigated by monitoring the absorbance change at 565 nm in dichloromethane solution. The reaction had a first‐order dependence on oxidant and a fractional (one half) dependence on reactant. The stoi

Inhibition of oxidation of ascorbic acid

Inhibition of oxidation of ascorbic acid by EDTA

✍ M. V. L. Rao; L. V. L. Sastry; M. Srinivasan; V. Subrahmanyan 📂 Article 📅 1959 🏛 John Wiley and Sons 🌐 English ⚖ 442 KB 👁 1 views

Micellar effect on the reaction of picol

Micellar effect on the reaction of picolinic acid catalyzed chromium(VI) oxidation of dimethyl sulfoxide in aqueous acidic media: A kinetic study

✍ A. K. Das; S. K. Mondal; D. Kar; M. Das 📂 Article 📅 2001 🏛 John Wiley and Sons 🌐 English ⚖ 313 KB 👁 2 views

Kinetic study of the oxidation of L-phen

Kinetic study of the oxidation of L-phenylalanine by potassium permanganate in acid medium

✍ M. J. Insausti; F. Mata-PÉRez; M. P. Alvarez-Macho 📂 Article 📅 1995 🏛 John Wiley and Sons 🌐 English ⚖ 427 KB 👁 1 views

The kinetics of permanganate oxidation of L-phenylalanine in acid medium at a constant ionic strength has been investigated spectrophotometrically. An autocatalytic reaction was observed being autocatalyzed by a soluble form of Mn(1V). The reaction appears to involve a parallel consecutive reaction

Kinetic studies of the reactions of pent

Kinetic studies of the reactions of pentacyanoferrate(III) complexes with L-ascorbic acid

✍ Lu-Ming Lin; Ming-Huei Lien; Andrew Yeh 📂 Article 📅 2005 🏛 John Wiley and Sons 🌐 English ⚖ 155 KB

## Abstract The reduction of Fe(CN)~5~L^2−^ (L = pyridine, isonicotinamide, 4,4′‐bipyridine) complexes by ascorbic acid has been subjected to a detailed kinetic study in the range of pH 1–7.5. The rate law of the reaction is interpreted as a rate determining reaction between Fe(III) complexes and t