Abstract
By spectrophotometry and by a liquid-liquid distribution method, the rate and equilibrium of the association of 2- thenoyltrifluoroacetone (Htta) with trioctylphosphine oxide (TOPO) in carbon tetrachloride-aqueous 0.1mol dm-3 perchlorate solution systems were studied. The effect of this association on the rate and equilibrium of the solvent extraction of copper(II) in the liquid-liquid system containing these extractants was examined. The associate of these reagents in carbon tetrachloride at equilibrium was concluded to contain one TOPO, one water, and one keto form Htta molecule. The change in the distribution ratio of Htta during the two-phase agitation was larger in the presence of TOPO. The extraction of copper(II) from the aqueous phase with Htta in the presence of TOPO was higher just after the start of two-phase agitation and it decreased gradually until the equilibrium was reached. The rate of this decrease of copper(II) extraction was explained in terms of the rate of decrease in the Htta and TOPO concentrations due to their association in the organic phase.
