Solvent extraction of indium(III) with bis(2-ethylhexyl) phosphinic acid in toluene

Extraction equilibrium data is obtained for distribution of indium(III) bet ween bis(2-ethylhexyl) phosphinic acid dissolved in toluene and acidic aque ous nitrate media, The stoichometry of the extracted species is determined on the basis of slope analysis and IR spectra, The extraction of indium(III ) proceeds by a cation exchange mechanism and the extracted species is InR3 . 3HR. Temperature dependence of the extraction equilibrium is examined hy temperature variation method to estimate apparent thermodynamic functions ( Delta H, Delta S and Delta G). The extraction process is exothermic in natu re and an increase in temperature is not favorable.