Kinetics of electrode reaction of Eu3+/Eu2+ studied by cyclic voltammetry and tast polarography

1990 ◽  
Vol 55 (7) ◽  
pp. 1666-1672 ◽  
Author(s):  
Jaroslav Němec ◽  
Tomáš Loučka
Keyword(s):  
Cyclic Voltammetry ◽  
Kinetic Parameters ◽  
Electrochemical Behaviour ◽  
Mercury Electrode ◽  
Electrode Reaction ◽  
Dropping Mercury Electrode ◽  
Sulphate Media ◽  
First Time ◽  
Kinetics Of ◽  
The Eu

The electrochemical behaviour of europium at the dropping mercury electrode was studied in the medium of 1M-NaClO4, 1M-NaCl, 1M-NaNO3, and 1M-Na2SO4. The curves obtained by Tast polarography and the kinetic parameters (ks, α) for the Eu3+/Eu2+ system in the medium of perchlorate and chloride solutions are in accord with the results published earlier. The kinetic parameters in nitrate and sulphate media are given for the first time. In the medium of nitrates, the electrode reaction is probably accompanied by a chemical reaction.

Application of Cyclic Chronopotentiometry to the Study of Slow Charge Transfer Reactions at the DME and the SMDE

1996 ◽  
Vol 61 (10) ◽  
pp. 1432-1444 ◽  
Author(s):  
Ángela Molina ◽  
Joaquín González ◽  
Carmen Serna
Keyword(s):  
Charge Transfer ◽  
Kinetic Parameters ◽  
Mercury Electrode ◽  
Electrode Reaction ◽  
Time Response ◽  
Transfer Reactions ◽  
Formal Potential ◽  
Dropping Mercury Electrode ◽  
Charge Transfer Reactions ◽  
Reaction Equations

In this work we apply cyclic chronopotentiometry to analyze charge transfer reactions at spherical electrodes, highlighting the influence of electrode curvature and the formation of amalgam on the potential-time response. Moreover, methods are proposed for determining the formal potential and the kinetic parameters of the electrode reaction. Equations obtained for the dropping mercury electrode are transformed to those corresponding to a static mercury drop electrode and a plane electrode.

Etude polarographique de l'antimoine(III) et (V) dans le fluorure d'hydrogène anhydre et dans ses mélanges avec l'eau

1978 ◽  
Vol 56 (5) ◽  
pp. 703-708 ◽  
Author(s):  
Jacques Devynck ◽  
Bernard Tremillon ◽  
Hugues Menard ◽  
Germain Comarmond
Keyword(s):  
Electrochemical Reaction ◽  
Electrochemical Behaviour ◽  
Mercury Electrode ◽  
Analytical Applications ◽  
Dropping Mercury Electrode

The electrochemical behaviour of Sb(III) and Sb(V) in water–HF mixtures (2.5 to 50% HF) and in anhydrous HF is described. A Teflon capillary dropping mercury electrode is proposed for polarographie investigations in these fluorinated media. It is shown, by classical or puise polarography, that Sb(III) can be reduced to Sb(0), as in acidic non-fluorinated media. The electrochemical reaction becomes reversible by addition of Cl−, Br− or I−. Sb(V) is not electroactive in the various HF-media, except when it is introduced as the SbCl5. In this case, the two polarographie waves of Sb(V) disappear with time because of SbF6− formation. Analytical applications to the determination of Sb(III) in water–HF and in anhydrous HF are discussed.

Electrochemical studies of Schiff base compounds derived from antipyrine nucleus in ethanolic buffer solutions

2000 ◽  
Vol 78 (9) ◽  
pp. 1170-1177 ◽  
Author(s):  
Ibrahim S El-Hallag ◽  
Gad B El-Hefnawy ◽  
Youssef I Moharram ◽  
Enass M Ghoneim
Keyword(s):  
Schiff Base ◽  
Electrochemical Behaviour ◽  
Electrochemical Techniques ◽  
Mercury Electrode ◽  
Electrode Reaction ◽  
Limiting Current ◽  
Electron Transfer Process ◽  
Buffer Solutions ◽  
Mechanistic Pathway ◽  
Electrochemical Parameters

The electrochemical behaviour of Schiff base compounds derived from an antipyrine nucleus was investigated in 30% (v/v) ethanolic buffer solutions (pH 3-11) using various electrochemical techniques at mercury electrode. The results showed that, the total limiting current of each of the studied compounds corresponds to 2-electron transfer process. The mechanistic pathway of the electrode reaction of the investigated compounds at mercury electrode, the effect of the medium, and the evaluation of the electrode reaction parameters were illustrated and discussed.Key words: Schiff base, antipyrine nucleus, electrode reaction, electrochemical parameters, cyclic voltammetry.

Analysis of the Electrode Kinetics of Ni(II) Reduction in Thiocyanate Media on the Dropping Mercury Electrode

2000 ◽  
Vol 65 (3) ◽  
pp. 326-342
Author(s):  
María S. Crespo-Pinilla ◽  
Fernando Mata-Pérez ◽  
Rosa M. Villamañán
Keyword(s):  
Ionic Strength ◽  
Compensation Effect ◽  
Supporting Electrolyte ◽  
Mercury Electrode ◽  
Electrode Kinetics ◽  
Surface Process ◽  
Experimental Conditions ◽  
Dropping Mercury Electrode ◽  
Kinetics Of

A study of two prewaves of the Ni(II)-SCN- system was carried out under the experimental conditions when the influence of electroreduction of SCN- is negligible. Kinetics of Ni(II) reduction in thiocyanate media on the dropping mercury electrode was studied by DC Tast Polarography (DCTP) via determination of Koutecký's parameter χ; the influence of different variables was analyzed. The study of prewaves was performed using various polarographic techniques. Values of χ depend on the SCN- concentration, pH, ionic strength (Ψ-effect) and on the nature of the supporting electrolyte. The number of electrons n, the transfer coefficient α, the stoichiometric number ν, ∆H≠, and ∆S≠ were determined (compensation effect). The first prewave has character of a reaction in the solution, the second prewave is a surface process. Main features of both mechanisms are common: catalytic nature, one-electron step discharge and the rate-determining process between species of opposite charges.

Behaviour of disubstituted dithiocarbamates at the mercury electrode

1975 ◽  
Vol 28 (1) ◽  
pp. 21 ◽  
Author(s):  
TH Randle ◽  
TJ Cardwell ◽  
RJ Magee
Keyword(s):  
Surface Film ◽  
Electrochemical Behaviour ◽  
Mercury Electrode ◽  
Alkyl Substituent ◽  
Electrode Reaction ◽  
Anodic Wave ◽  
Alkyl Groups ◽  
Product Film ◽  
Triton X ◽  
General Method

The electrochemical behaviour at the mercury electrode of a series of sodium dithiocarbamates in aqueous solution has been investigated. Although the overall electrode reaction mechanism is the same as that for sodium diethyldithiocarbamate in each case, the current flowing in the main anodic wave is determined by the nature of the film of the particular insoluble mercury(II) dithiocarbamate deposited on the electrode and varies with the alkyl substituent group in the dithiocarbamate. A porous, loosely bound film which periodically bursts, causing localized stirring and large irregular currents, was indicated for large bulky alkyl groups (e.g. butyl) while for small or planar alkyl groups (e.g. methyl, tetramethylene) current inhibition was observed, suggesting a compact surface film. The influence of the surfactant Triton X-100 on the product film has also been examined. Linear sweep chronoamperometry is recommended as a general method of analysis for dithiocarbamates as the electrolysis time (and therefore the film thickness) can be selected to avoid the above interferences.

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