Direct current polarography in the presence of alternating voltages. II. Irreversible systems

1954 ◽  
Vol 7 (4) ◽  
pp. 312 ◽  
Author(s):  
GS Buchanan ◽  
RL Werner
Keyword(s):  
Direct Current ◽  
Mercury Electrode ◽  
Dropping Mercury Electrode ◽  
Alternating Voltage

The superposition of a small alternating voltage on the normal D.C. voltage applied at the dropping mercury electrode (D.M.E.) results in the case of irreversible systems in a marked displacement of the entire D.C. wave, in contradistinction to those cases known to be reversible. Such a displacement has been interpreted in terms of an ionic picture. The cases examined were ZnO2--, Fe++, Ni++, Sb+++ in the presence of varying concentrations of Cl-, and Cd++ in the presence of varying concentrations of cyclohexanol. The effect of frequency was investigated.

Direct current polarography of the ferrous-ferric oxolate system in the presence of alternating voltages

1958 ◽  
Vol 11 (1) ◽  
pp. 9
Author(s):  
P Beckmann ◽  
GS Buchanan
Keyword(s):  
Direct Current ◽  
Active Substance ◽  
Mercury Electrode ◽  
Surface Active Substance ◽  
Active Materials ◽  
Wave Potential ◽  
Half Wave ◽  
Dropping Mercury Electrode ◽  
Surface Active ◽  
Alternating Voltage

The effect of the superposition of a small alternating voltage on the normal direct voltage applied to the dropping mercury electrode (D.M.E.) was investigated in the case of the ferrous-ferric oxalate system. The wave obtained was of the type found previously for ions which are reversibly reduced at the D.M.E. (e.g. Cd++ etc.). That is, the rectification of the A.C. produced a D.C. wave (the Z wave) which crossed the normal D.C. wave (the Y wave) at the half-wave potential (E�), When surface active materials were added (e.g. cyclohexanol) the reduction became " irreversible " and at certain concentrations of the surface active substance a maximum appeared on the Y wave of a somewhat unusual nature. The effect of a superposed alternating voltage was studied in these cases and it was found that the adsorption of the cyclohexanol was influenced by the presence of the alternating voltage.

Retardation of Cd2+and Zn2+ discharge at the dropping mercury electrode by adsorbed phenyl substituted phosphonium cations

1988 ◽  
Vol 66 (5) ◽  
pp. 1053-1058 ◽  
Author(s):  
A. Anastopoulos ◽  
A. Christodoulou ◽  
I. Moumtzis
Keyword(s):  
Direct Current ◽  
Mercury Electrode ◽  
Capacitance Measurements ◽  
Adsorption Characteristics ◽  
Dropping Mercury Electrode ◽  
Activated Complex ◽  
Phosphonium Cations

The effect of adsorbed propargyltriphenyl- and vinyltriphenylphosphonium cations on the discharge of Cd2+ and Zn2+ at dropping mercury electrode is studied by direct current polarographic measurements. Adsorption characteristics are determined by capacitance measurements. The size parameters of the activated complex and the surfactant particles are derived and an elucidation of the mechanism of the inhibited reaction is attempted.

Theory of alternating current polarography. I. Equation of the reversible AC polarographic wave

1954 ◽  
Vol 7 (3) ◽  
pp. 225 ◽  
Author(s):  
B Breyer ◽  
S Hacobian
Keyword(s):  
Mercury Electrode ◽  
Inorganic Ions ◽  
Alternating Current ◽  
Polarographic Wave ◽  
Dropping Mercury Electrode ◽  
Concentration Changes ◽  
In Virtue Of ◽  
Alternating Voltage ◽  
Polarographic Current

An equation for the A.C. polarographic current is derived from considerations of concentration changes produced at the dropping mercury electrode in virtue of the superposition of a small sinusoidal alternating voltage onto the direct potential, for the case of reversibly reduced inorganic ions. The equation predicts the magnitude of the A.C. polarographic current at any point on the polarogram.

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