Polarographic Behaviour of Dy(III) on Mercury Drop Cathode†

Abstract

The nature and behaviour of reduction of Dy(III) on a mercury drop cathode has been extensively investigated. It was observed that Dy(III) gave a single step well defined reduction wave in KCl in the entire range of pH 2.1 to 3.4. Above this pH value aquo ions have a predominant role. The reduction has been found to be diffusion controlled and variation in wave height and concentration was linear. The effect of pH, supporting electrolyte concentration
and Dy(III) concentration have been observed. The polarographic
reduction of Dy(III) is abnormal. It produces reversible, quasireversible
and irreversible reduction wave under distinct experimental
conditions. The log plot analysis of each of the polarograms revealed
that Dy(III) produces a reversible three electron wave at pH
2.6 to 0.5 mole dm^–3 KCl and 0.01% gelatin E_½, i_d and E_¾ – E_¼
values are –1.72 V, 3.9 and 19 mV respectively.