Electrode reactions of nickel(II) at mercury electrodes in aqueous solutions of azides

Abstract

The electrode processes of the Ni 2+ |Ni(Hg) system in aqueous azide solution at mercury electrodes have been investigated. It was found that NiN 3 + reacts directly with the electrode. Consequently at low azide concentrations the electrode reaction is preceded by the process of formation of that complex from aquonickel (II) ion. At higher concentrations ([N 3 − ]>2 m ) the complex [Ni(N 3 ) 4 ] 2− is in equilibrium with NiN 3 + which is irreversibly reduced. The very high value of the apparent cathodic transfer coefficient suggests a two-step electrode reaction with a slow transfer of the second electron.