Polarography in N,N-dimethylacetamide: Part II. Alkaline-earth metal ions

Abstract

D.c. polarography at the dropping mercury electrode, cyclic voltammetry at the stationary mercury electrode, and a.c. oscillopolarography at the streaming mercury electrode, were used for an investigation on anhydrous beryllium chloride and on the anhydrous perchlorates of magnesium, calcium, strontium and barium in 0.1 M solutions of tetraethylammonium perchlorate in N,N-dimethylacetamide. The nature of the limiting currents, the diffusion coefficients, the diffusion current constants, the half-wave potentials vs. an aqueous saturated calomel electrode, the oscillopolarographic incision potentials, and the anodic peak potentials in cyclic voltammetry, have been determined at 25.0°. The temperature-dependencies of the half-wave potentials and of the limiting currents were established between 20° and 40°. Reversibility tests were carried out by using logarithmic analysis, the temperature coefficient of the half-wave potential, the Kalousek commutator, oscillographic a.c. polarography, and the anodic stripping method. The effect of the presence of water in the solution was investigated and is discussed.