Abstract
LONDON. Faraday Society, July 6.—A. L. Marshall: The electrodeposition of zinc from sulphate solutions. With pure solutions, the efficiency of zinc deposition always increases with rising temperature; an explanation based on chemical polarisation is given. A convenient copper coulometer has been developed for measuring currents up to 15 amperes or more.—J. B. OSullivan: The application of the quinhydrone electrode to the measurement of PH valves in solutions containing copper ions and other divalent ions. The quinhydrone elecirode can be employed in many cases in which the ordinary hydrogen electrode cannot be used on account of its greater reducing power. This applies not merely to salts of copper, which are electro-positive towards hydrogen, but also to neutral or weakly acid solutions of the salts of such metals as tin, lead and nickel. The quinhydrone electrode is itself limited in its applicability by its reducing power. Thus it cannot be employed even in moderately acid solutions of the salts of mercury, silver or gold, which have normal electrode potentials of more than 0.7 volt.—F. M. Cray and G. M. Westrip: The preparation of solutions of standard hydrogen ion con centration and the measurement of indicator ranges in an acetone-water mixture. Solutions of standard hydrogen ion concentration ranging from PH 12.5-2.0 have been prepared and calibrated by means of the quinhydrone electrode in a solvent containing 10 volumes of water in 100 of acetone-water. These solutions have been used in the measurement of the PH ranges of a large number of indicators in the specified solvent. Their behaviour in these standard solutions is consistent with their PH values, as deter mined by the quinhydrone electrode, within 0.1 PH.
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Societies and Academies. Nature 116, 226–228 (1925). https://doi.org/10.1038/116226a0
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DOI: https://doi.org/10.1038/116226a0