Effect of the nature of organic solvents on their interaction with metal halides

Abstract: The radioactive tracer technique was used for studying the extraction and predicting the best conditions of separation of arsenic halides by organic solvents of different nature. Sulphuric acid was found to enhance the extraction of arsenic halides. Extraction of AsI₃ increases in the order cyclohexane <CCL₄ toluene <o-xylene <CHCl₄ and is quantitative by benzene and nitrobenzene. For a given extraction increases in the order AsCl₃<AsBr₃< <AsI₃. Spectral measurements were made on some solvents; at maximum absorption there was a linearity between absorbance and AsI₃ concentration up to 2·10⁻⁴ M for o-xylene and to 2.5·10⁻⁴ M for nitrobenzene.