Investigation of the Hg/HCl aq. system by capillary electrometers based on maximum bubble pressure method and by classical capillary electrometer Comparison of interfacial tension and double-layer capacity data

Abstract

The Hg/HCl aq. system was studied using capillary electrometers based on the maximum bubble pressure principle (that employed either an inverted capillary or a vertical capillary) and by the classical capillary electrometer. All three versions of the capillary electrometer yielded interfacial tension data of high precision, except that the modified capillary electrometer with a vertical capillary and the classical electrometer gave data of slightly lower quality over a narrow range of extreme negative polarization for 0.01 M HCl solution. Based on the electrocapillary and double-layer capacity measurements carried out on identical HCl solutions (0.01 M–1 M), it is shown that there exists a very good correspondence between the measured and derived quantities as compared to the agreement previously observed by Bockris and co-workers (who employed a classical capillary electrometer in their interfacial tension measurements).