The Behaviour of Lead in Iodide Medium at the Dropping Mercury Electrode. II. A.C. Polarographic Study

1962 ◽  
Vol 15 (4) ◽  
pp. 734 ◽  
Author(s):  
VS Srinivasan ◽  
AK Sundaram
Keyword(s):  
Mercury Electrode ◽  
Polarographic Study ◽  
Lead Iodide ◽  
Dropping Mercury Electrode

An a.c. polarographic study of the lead-iodide system is described. Three peaks are obtained. The second and third peaks are proved to be due to a combined tensammetric-polarographic process.

The Behaviour of Lead in Iodide Medium at the Dropping Mercury Electrode. I. D.C. Polarographic Study

1962 ◽  
Vol 15 (4) ◽  
pp. 729 ◽  
Author(s):  
VS Srinivasan ◽  
AK Sundaram
Keyword(s):  
Mercury Electrode ◽  
Polarographic Study ◽  
Lead Iodide ◽  
Low Concentrations ◽  
Dropping Mercury Electrode ◽  
High Concentrations ◽  
Adsorption Wave ◽  
Second Wave

The polarography of lead in the iodide medium has shown that an irreversible wave is obtained at moderate concentrations of lead, whereas at high concentrations two waves are obtained and at low concentrations a single reversible wave is obtained. This explains the irreversible waves obtained by the earlier workers who have mainly worked in the region of 0.4mM of lead. From a study of the effect of the head of mercury, temperature, etc. it is shown that the second wave is an adsorption wave resulting from the adsorption of lead iodide complexes at the dropping mercury electrode.

A Polarographic study of some Wurster salts

1958 ◽  
Vol 11 (2) ◽  
pp. 104 ◽  
Author(s):  
JA Friend ◽  
NK Roberts
Keyword(s):  
Aqueous Solution ◽  
Acetic Acid ◽  
Formation Constant ◽  
Platinum Electrode ◽  
Mercury Electrode ◽  
Diffusion Current ◽  
Polarographic Study ◽  
Polarographic Investigation ◽  
Dropping Mercury Electrode ◽  
Hydrolysis Of

Four related Wurster salts are subjected to a polarographic investigation. In the case of Wurster's blue, results from the dropping mercury electrode, stationary platinum electrode, and rotated platinum electrode are compared. The Wurster salt of p-phenylenediamine is unstable in aqueous solution but is fairly stable in a mixture of methanol, acetic acid, and water and the decrease of diffusion current with time indicates a disproportionation. Wurster's red is also unstable in aqueous solution. In the solvent methanol, acetic acid, and water, a wave is observed with the stationary platinum electrode whose E� compares favourably with the potentiometric E?0. Evidence from the three types of electrodes mentioned previously indicates two one-electron waves for Wurster's blue. The semiquinone formation constant qualitatively appears much greater than that reported from potentiometric work. Decrease of diffusion current with time is perhaps due to a disproportionation (the very unstable di-imine has been shown to revert to the radical in aqueous solution). Polarographic waves given by the Wurster salt of diaminodurene suggest that the radical does not exist in aqueous solution. Waves corresponding to the original amine and duroquinone (formed by hydrolysis of the di-imine) are obtained.

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