Studies on Overvoltage

Abstract

This is a continuation of studies on overvoltage. Attention is confined here to the natural decay on open circuit of cathode potentials at platinized platinum electrodes. Four factors were altered: first, a still solution saturated with hydrogen was used; second, a stirred solution saturated with hydrogen; third, a still solution saturated with nitrogen; and fourth, a stirred solution saturated with nitrogen. The object in each case was to produce a condition that would influence the rate of diffusion of active material away from the electrode-solution interface. Previous experiments had indicated that cathode polarization potentials are determined by the activity of atomic hydrogen and hydrogen ions at the electrode-solution interface. The work was designed to provide information on this theory. All of the data obtained support the theory. * This paper constitutes a portion of the dissertation submitted by Myron B. Towns to the Faculty of the Horace H. Rackham School of Graduate Studies, University of Michigan, in partial fulfillment of the requirements for the Ph.D. degree. Manuscript

Osmotic Coefficients and Mean Activity Coefficients of Uni-univalent Electrolytes in Water at 25°C

“…Isopiestic measurements have been made by Robinson (0.1-4 m) [23,150], Pencier and Marcus (2.8-8.9 m) [157], and Makarov, Vlasov, and Azarko (3 9.1 m) [158]. [162], and Harned and from 0.1 to 0.9 m. Vapor pressures were measured by Stokes (5;085-13.834 111) [145] and Kangro and Groeneveld (1.0-27.0) [126] and isopiestic measurements by Stokes (2-29 m) [165]. B*= 1.21 (3 = 6.1509 X 10-2 C = -2.9784 X 10-3 D = 1.3293 X 10-3 E = -1.1134 X 10-4 F = 3.5452 X 10-6 G = -3.9985 X a -for molalities above 6.0, the data of references [159] and [167] differ fairly widely; average values are as follows: m <P "'I m measurements to obtain activity coefficients for the concentration ranges, 0.005-0.020 N [170] and 0.003-0.015N [132].…”