(1) 7 N ammonium sulphate solution and 10, 15, 20, 25, 30, and 36 N sulphuric acid are electrolysed without diaphragm. 10 N sulphuric acid is also electrolysed with diaphragm. Current efficiency is observed for various current densities and temperatures, the latter being 5°, 15°, and 25°C. (2) The mechanism of the anodic formation of persulphuric acid is discussed from the relation between the temperature and current efficiency, and the fresh results of electrolyses described in this paper can be accounted for by the view that persulphuric acid is formed by the oxidation of sulphuric acid with the anodic oxygen which was proposed in Part I, and confirmed in Part II of this investigation. (3) An interesting similarity is noticed which exists between the electrolysis of 15 N sulphuric acid made at various temperatures and that of the same made with various OH′-ion concentrations.
(1) It is recognized that the tetradecenoic acid of “Tohaku” oil is tsuzuic acid. (2) The authors have prepared pure obtusilic, linderic, and tetra-decenoic acids from the “Tohaku” oil, and have determined their physical properties and the melting points of their crystalline derivatives.