The study of hydroxyl complexation processes in Fe(III)–Fe(II)–Na(H)CI–H2O system

Abstract

Hydroxyl complexation in the Fe(III)–Fe(II)–Na(H)CI-H2O system at different ionic strengths of the solution, temperature 308.16 K, was studied by the Clark–Nikolsky oxidation potential method. The formation of the following mono- and binuclear coordination compounds is shown [Fe(OH)(H2O)5]2+; [Fe2(OH)2(H2O)10]4+; [Fe(OH)2(H2O)4]+ ; [Fe(OH)3(H2O)3]0. It was found that Fe(II) does not form hydroxo complexes at the studied concentration parameters, and the pH range from 1.0 to 3.0. Above this pH value, Fe(III) hydrolyzes and forms a brown precipitate.