Titulações potenciométricas de cátions metálicos tendo como eletrodo indicador o sistema Cu/Cu(II)-EDTA Potentiometric titrations of metal cations with edta using the Cu/Cu(II)-EDTA system as indicator electrode

Abstract

In potentiometric titrations of metal cations with EDTA the Hg/HgY2- system is usually used to detect the end point. However, the use of mercury has been discouraged in analytical procedures due to its toxicity. In this work the Cu/CuY2- system was used as indicator electrode for potentiometric titrations of some metal cations with EDTA. The solutions of Cu2+, Cd2+, Mn2+, Co2+ and Zn2+ were titrated with Na2EDTA solution in the presence of a small concentration of the CuY2- complex using a copper wire as indicator electrode. The potentiometric titrations with the Cu/CuY2- system showed good correlation when compared with an Hg/HgY2- system.

Keywords

• potentiometry
• Cu/Cu-EDTA system
• EDTA titration