A New Method for Constant Estimate Stability of Complex With Edta

Abstract

The present work describes a new methodology in analytical chemistry, which makes it possible to calculate the stability constant (equilibrium or formation) of the coordination compounds generated between all metallic cations in the periodic table, except for alkali metals (group 1 ) together with the ethylene diamine tetraacetic acid binder. The system is simple to use, inexpensive, and allows the knowledge of the size of the conditional formation constants for all metals coordinated with the complexing agent to be investigated at any pH value investigated. In addition, the method is also extensive for other binders having the same chemical reaction property as ethylenediamine tetraacetic acid performs with metal ions in the same stoichiometric bonding ratio. For the execution of this study, solutions of copper (II) cation was employed, at a concentration of 1.0x10-2 mol L-1 and the complexing agent, also presenting the same concentration of metal. The assay was conducted in a buffering system consisting of ammonium hydroxide and ammonium chloride salt at a constant pH of 10.0. The method allows its use in experimental procedures developed both in a chemical laboratory and in a classroom, used during the theoretical activities. The chelating agent has a wide spectrum of application in the food product industries, also in the generation of cleaning materials in general, as well as in the photography industry, textile production, paper manufacture and the like, rubbers and the like, polymers and derivatives, among other production lines intended for its manufacture for human consumption.

Uma Nova Sistemática Para a Determinação Das Constantes Do Potencial Padrão De Redução De Sistemas Redox

“…A correta manipulação dos dados gerados nesta titulação permite a obtenção de vários outros diagramas e, a sua devida interpretação, possibilita a determinação da constante do potencial padrão de redução (E o ) dos agentes oxidantes e redutores. A construção e o emprego de planilhas eletrônicas do EXCEL, como ferramenta analítica de geração e interpretação de dados, é bastante documentada na literatura (HARRIS, 2001;PEREIRA, 2019;PEREIRA, 2016).…”

“…O emprego da equação de Nernst para os cálculos dos potenciais registrados no curso de uma titulação redox potenciométrica tem largo amparo na literatura, (BASSET, 1992;CIENFUEGOS, 2000;HARRIS, 2001;JOSEPH, 2000;GONÇALVES, 2001;OHLWEILER, 1976;SAWYER, 1984;SKOOG, 2002;SKOOG, 1997;SKOOG, 2008;TICIANELLI, 1998;VALCARCEL, 2000;SCHOLZ, 2002;EWING, 1972;EWING, 1972;HAMILTON, 1960). Enquanto a substituição dos termos das concentrações pelo cálculo das quantidades de matéria foi apresentada pelos autores anteriormente (PE-REIRA, 2016;PEREIRA, 2019).…”