Effect of surface active cations undergoing interfacial rearrangements on deposition type electrode reactions

1988 ◽  
Vol 53 (4) ◽  
pp. 732-742 ◽  
Author(s):  
Anastos Anastopoulos ◽  
Anastasia Christodoulou
Keyword(s):  
Rate Constants ◽  
Mercury Electrode ◽  
Size Ratio ◽  
Inhibition Mechanism ◽  
Electrode Reactions ◽  
Dropping Mercury Electrode ◽  
Surface Active ◽  
Activated Complex ◽  
Effect Of Surface

The influence of the adsorption of methyltriphenyl- and cyclopropyltriphenylphosphonium cations on simple deposition reactions of Cd2+ and Zn2+ at the dropping mercury electrode, is studied by polarographic techniques. The size parameters of the activated complex, r≠, and adsorbate particles, ri, are determined and discussed. It is shown that for substances undergoing interfacial rearrangements, i.e. condensation and reorientation, the values of the size ratio r≠/ri can hardly be correlated to independently determined values of r≠ and ri. Electrode coverages are related to formal rate constants and an elucidation of the inhibition mechanism is attempted.

The Effect of p-Toluidine on the Two-Step Electroreduction of Zn(II) in Water-Methanol and Water-Dimethylformamide

1999 ◽  
Vol 64 (4) ◽  
pp. 585-594 ◽  
Author(s):  
Barbara Marczewska
Keyword(s):  
Electron Transfer ◽  
Binary Mixtures ◽  
Rate Constant ◽  
Rate Constants ◽  
Electrode Surface ◽  
Mercury Electrode ◽  
Forward Rate ◽  
Solvent Molecules ◽  
Activated Complex

The acceleration effect of p-toluidine on the electroreduction of Zn(II) on the mercury electrode surface in binary mixtures water-methanol and water-dimethylformamide is discussed. The obtained apparent and true forward rate constants of Zn(II) reduction indicate that the rate constant of the first electron transfer increases in the presence of p-toluidine. The acceleration effect may probably be accounted for by the concept of the formation on the mercury electrode an activated complex, presumably composed of p-toluidine and solvent molecules.

scholarly journals KINETIC MODEL OF THIOUREA DIOXIDE DECOMPOSITION IN AQUEOUS SOLUTIONS OF DIFFERENT ACIDITY

2018 ◽  
Vol 61 (12) ◽  
pp. 87-93
Author(s):  
Yuri V. Polenov ◽  
Gleb A. Shestakov ◽  
Elena V. Egorova
Keyword(s):  
Kinetic Model ◽  
Rate Constants ◽  
Silver Chloride ◽  
Mercury Electrode ◽  
Calculated Data ◽  
Correlation Coefficients ◽  
F Test ◽  
Thiourea Dioxide ◽  
Dropping Mercury Electrode ◽  
The Individual

A stoichiometric mechanism for full thiourea dioxide decomposition in aqueous solution under pH of 4.0 is proposed based on dependences of concentrations of thiourea dioxide and its decomposition products on the time and literature data. The concentration of thiourea dioxide was measured via iodometry, while the intermediates were quantified using the polarography. Polarography was carried out in glass two-electrode electrochemical cell by means of PU-1 polarograph in differential mode. Dropping mercury electrode was used as working one and silver chloride as a reference one. Rate constants for individual stages are obtained via mathematical modeling, presented a system of differential equations. Absolute errors of rate constants, correlation coefficients, and F-factors were also calculated. Verification of supposed kinetic model was conducted using the comparison between experimental and calculated concentrations, F-test and the calculated values of correlation coefficients of the individual stages of the process. Supposed kinetic model of decomposition consists of a number of consequent stages including various compounds such as sulfur monoxide, thiosulfuric, sulfuric, dithionic, hydrosulfuric acids as intermediates was used for previously obtained data for pH of 8.85. To test the universality of supposed model, we simulated kinetics of thiourea dioxide decomposition reaction at pH of 8.85. Experimental kinetic data were taken from literature. The initial approximations of the individual stages constants were taken from previous calculations. Analysis of calculated data: concentration values, F-test, correlation coefficients allowed to conclude about the applicability of proposed mechanism for the process of thiourea dioxide decomposition in a weakly alkaline medium.

scholarly journals Analysis of Cationic Surface Active Agents Using DME and Its Relevance to Their Adsorption

1987 ◽  
Vol 4 (1-2) ◽  
pp. 53-57
Author(s):  
J. Matysik ◽  
H. Kroszka ◽  
A. Persona
Keyword(s):  
Mercury Electrode ◽  
Analytical Determination ◽  
Surface Active Agents ◽  
Dropping Mercury Electrode ◽  
Surface Active

The paper describes an application of dropping mercury electrode (DME) for analytical determination of certain cationic surface active agents and their mixtures and presents obtained thermodynamical data of adsorption of investigated substances.

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