UBC Theses and Dissertations
Investigation of the direct current determination of electrolytic conductivity : measurement of strain potentials McFadden, William Hamilton
The cell constant of a direct current conductivity cell was measured using as a standard 0.1M and 0.01M potassium chloride solutions and specific conductivity data obtained by G. Jones and M. Prendergast. The results obtained for either of the solutions were exact to within one or two parts in ten thousand, but a difference of 0.6% existed between the two cell constant values. In order to investigate more exactly the nature of this variation, other concentrations were measured using as a standard the data obtained by T. Shedlovsky, A.S. Brown, and D.A. Maclnness. Certain factors in the design of a direct current cell have been considered and suggestions for future work offered. Studies have been made of the anodic properties of strained copper wire in the cell Cu (strained) ⃒ CuSO₄ ⃒ Cu (normal). Two copper wires were immersed in copper sulphate solution. Weights were added to one of these and the potential difference measured potentiometrically or with a vacuum tube volt-meter. The results obtained show that (1) the relaxation of this potential is approximately exponential, (2) very little potential is developed until a critical strain is applied, (3) after a certain strain has been applied the peak potential developed becomes constant with increasing strain, (4) the magnitude of the effect is dependant on the concentration of the solution, (5) the magnitude and direction (anodic or cathodic) of the potential is dependant upon the components of the electrolyte.
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