Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 2005-02-01

Chemical behavior of tungstate solutions. Part 1. A spectroscopic survey of the species involved.

Thierry Barré, Laurent Arurault, François X Sauvage

Index: Spectrochim. Acta. A. Mol. Biomol. Spectrosc. 61(4) , 551-7, (2005)

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Abstract

This study is focused on the composition and the evolution of tungstate ions solutions as a function of pH and increasing concentrations. The Raman analysis showed that, during the titration of the tungstate solutions, WO4(2-), HWO4- ions and probably W2O7(2-) , HW2O7(2-) and H2W2O7 solvated species could exist in aqueous solutions. For diluted solutions, additions of a strong acid does not cause any precipitation, whereas the formation of the unstable solid tungstic acid (H2WO4 or WO3.H2O) could occur in concentrated solutions.