Studies on the Diffusion Currents for Tl (I) as Depolarizer with Dropping Mercury Electrodes of Different Geometry

Diffusion currents of Tl (l) over an extended range of concentration (0.5 mM to 40 mM) have been recorded in 2 M NaNO3 with a vertical, horizontal, inclined at 45° and pointed upward dropping mercury electrode. Except for horizontal d.m.e., a linear relationship is exhibited between id and C for the other electrodes. The diffusion current (id) is maximum for the capillary pointed upward and least for the horizontal d.m.e. This has been further substantiated from the record of current-time curves for single drops. The half-wave potential (E1/2) varies with the concentration of the depolarizer. At higher concentrations irreversible character becomes pronounced.