Preparation and properties of iron molybdates. I-investigation on the interaction between Mo(VI) and Fe(III) as a function of pH of the paramolybdate solution

Abstract

The equilibrium processes of formation of various forms of polymolybdate ions during alkaline hydrolysis of diluted ammonium paramolybdate solutions have been investigated. The discrete existence of certain polymolybdate ions has been established by a study of the precipitation processes with Fe(III) ions using three pre-fixed Mo/Fe atomic ratios. Chemical analysis and UV spectroscopy measurements of the equilibrium filtrates have been made and the Mo/Fe atomic ratios in the equilibrium precipitates have been determined. A conclusion has been drawn about the existence of a homologous series of iron molybdates.