Showing papers on "Supporting electrolyte published in 1970"

The ionic double layer at the interface

Abstract: An experimental study of the adsorption of potential-determining ions at the zincite (ZnO) aqueous solution interface is reported. Changes in solubility of the oxide with pH are shown to limit adsorption measurements to the pH range 8–10. The pzc of ZnO, as determined by the intersection of adsorption curves at low ionic strength, is shown to depend on the method of preparation and on the nature of the supporting electrolyte.

An Experimental Study of Nonuniform Current Distribution at Rotating Disk Electrodes

Abstract: The theoretical predictions of Newman (1, 2) concerning the existence of a nonuniform current distribution at rotating disk electrodes have been verified in media containing insufficient supporting electrolyte. Measurements of the thickness of copper films deposited on a platinum disk yield results qualitatively of the form predicted by Newman. The primary current distribution is approached at currents corresponding to a small fraction of the limiting convective diffusion current in the absence of appreciable supporting electrolyte, while a uniform current distribution is found in the limiting current region. Nonuniform current distribution at a disk electrode has been found to have significant effects on the collection efficiency of a ring‐disk electrode. These effects depend markedly on the geometry of the electrode. Similar behavior has been noted in the currents observed at "shielded" rings of ring‐disk electrodes. Under conventional polarographic conditions in solutions containing fifty‐ to a hundred‐fold excess of supporting electrolyte, no significant deviations from a uniform disk current distribution could be detected.

The adsorption of methyl red at the dropping mercury electrode

Abstract: Surface excess concentrations of methyl red at the mercury-solution interface have been determined at pH 7.00, 9.80, and 12.30 from electrocapillary measurements using 0.lM sodium nitrate as supporting electrolyte. The results are interpreted in terms of a reorientation of the methyl red anion between -0.4 V and -0.6 V (v. S.C.E.)

Electrochemical treatment of material produced by reaction in electrochemical cell

Abstract: A CHEMICAL REACTION IS CONDUCTED IN AN ELECTROCHEMICAL CELL TO PROVIDE A MATERIAL TO BE ACTED ON AT A CELL ELECTRODE. THUS, A SINGLE STEP OZONOLYSIS OF A CYCLIC OLEFIN WITHIN IN SITU ELECTROCHEMICAL REDUCTION TO PROVIDE A DIALDEHYDE AND/ OR A KETONE IS DISCLOSED. AN ELECTROCHEMICAL CELL, THE HYDROGEN-DEPOLARIZED ANODE OF WHICH CAN BE REPLACED BY A CONVENTIONAL PLATINUM, CARBON, NICKEL, ETC. ANODE, SUITABLY WITH A DIAPHRAGM SEPARATING IT FROM THE CATHODE IS USED, HAVING IN THE CELL AN ELECTROLYTIC SOLVENT, E.G., AN ALCOHOL SUCH AS METHANOL AND A SUPPORTING ELECTROLYTE SUCH AS AN ACID, E.G., ACETIC ACID OR A SALT THEREOF. THE OLEFIN WHICH CAN BE ONE LEADING TO THE FORMATION OF AN ALPHA, OMEGADIALDEHYDE, E.G., CYCLODODECENE, IS FED TO THE CELL TO WHICH AIR AND AZONE ARE ALSO FED INTO A LOWER PART OF THE CELL BELOW THE CATHODE, THE AIR AND OZONE BEARING SPARGED IN ONE EMBODIMENT INTO THE CELL LIQUID BELOW THE ELECTRODE CREATING A STIRRING OR MIXING ACTION AT THE CATHODE TO WHICH THE OLEFIN IS ALSO FED. COOLING IS PROVIDED TO MAINTAIN THE TEMPERATURE OF THE CELL. THE LOW CONCENTRATION OF OZONIDE IN THE OPERATION IS A FEATURE OF THE INVENTION TO PREVENT DEGRADATION AND OTHER PROBLEMS ENCOUNTERED WITH OZONIDES.

The Effect of the Weak Completing Nature of NaF, NaN3, and NaC3H3O3 Supporting Electrolytes on the Electrocatalysis of Nickel(II) Reduction in the Presence of Organic Amines

Abstract: Contrary to the results obtained in essentially noncomplexing supporting electrolyte media (NaClo4, NaN03, NaCl and NaBr), the kinetic limited currents of the catalytic prewaves obtained for the polarographic reduction of Ni(II) in the presence of organic amines (o-phenylenediamine, pyridine, etc.) employing weakly complexing supporting electrolytes (NaF, NaN3, and NaC2H3O2) do not correlate with ⊘2 potentials as predicted by simple double layer theory. However, the limiting current does correlate with the ligand exchange rates for Ni(H2O)5X+ type complexes (where X = F−, N3 − and C2H3O2 −) with an organic ligand. These results lead to a general mechanism for the electrocatalysis mechanism of Ni(II) reduction.

Synthesis and polarographic studies of beta-substituted phenylcystine derivatives

Abstract: The synthesis of N-benzoyl-threo-β-p-substituted phenylcystine ethyl esters via azlactone intermediates is reported. A polarographic method for their determination using 0.1 M sodium acetate in anhydrous methanol as the supporting electrolyte was investigated. The relationship between the half-wave potential and the Taft polar substituent constant, σ*, was studied.

The determination of sodium mercaptobenzothiazole and benzotriazole in inhibited glycol products

Abstract: A polarographic method is described for the determination of sodium mercaptobenzothiazole and benzotriazole in unused inhibited glycol mixtures.Sodium mercaptobenzothiazole can be determined directly on the sample by using 0·2 M hydrochloric acid as supporting electrolyte and measuring its polarographic wave at –1·26 V. This is an extremely sensitive method and concentrations as low as 1 p.p.m. can be determined in addition to the normal concentration level of 0·2 per cent.Benzotriazole is also determined polarographically at–1·14 V, with the same electrolyte, after initial separation of the sodium mercaptobenzothiazole on an anion-exchange resin in the chloride form.Determinations have been successfully carried out in the presence of anti-freeze mixtures containing sodium benzoate, borate, nitrite and phosphate inhibitor systems.

High-Frequency Polarography of Cyanide Ion

Abstract: ? The HF polarographic characteristics of cyanide ion are studied experimentally. As the supporting electrolyte is recommended 0.1N NaOH. For the analytical application one should pay attention to the interfering effect of chloride ion.