THE ELECTRODE REACTION OF HEXAAMMINECHROMIUM(III) IN THE PRESENCE OF ETHYLENEDIAMINETETRAACETATE AND NITRATE IONS

Abstract

Abstract It has been confirmed experimentally that Cr(NH3)63+ gives a catalytic wave on its polarogram in the presence of EDTA and NO3− ions according to the EC(C′E′)n type mechanism; Cr(NH3)62+ which is produced on the electrode surface by the electrochemical reaction reacts with EDTA rapidly to form Cr(II)-EDTA (denoted as EC), which in turn gives a catalytic wave in the presence of NO3− ions (denoted as (C′E′)n). In addition, it was suggested that the reduction intermediates of nitrate ion oxidize Cr(H2O)p(NH3)6−p2+ at an appreciable rate, which nitrate ion itself does not.