Studies in Non-Faradaic Electrolysis with Systematic Variation of Cation and Anion

Department of Physical Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Calcutta-700 032

Manuscript received 10 June 1981, accepted 10 March 1983

Electrolysis of aqueous solutions of different electrolytes reveals that (i) the occurrence of non-Faradaic behaviour is a general phenomenon with practically all electrolytes provided the current density and/or electrolyte concentration is low ; the behaviour tends to become Faradaic at higher concentration, the threshold concentration depending upon the nature of the electrolyte ; (ii) of the different organic and Inorganic salts of alkali metals, sulphates produce more anomalous results, the extreme anomaly being associated with the sodium sulphate solution ; (iii) with heavy metal sulphates, electrolysis causes deposition of metal at the cathode and no co-liberation at the anode ; (iv) an oxidant and a reductant serve as depolariser at the cathode and anode, respectively and the gas liberation at the depolariser·reactive electrode is suppressed, the gas volume at the other electrode being nearly Faradaic with no or a little co-liberatien.