AN ISOPIESTIC INVESTIGATION OF DI(2-ETHYLHEXYL)- PHOSPHORIC ACID AND TRI-n-OCTYLPHOSPHINE OXIDE IN n-OCTANE

摘要

Isopiestic measurements are presented in which octane solutions of di (2-ethylhexyl) phosphoric acid (DPA) and tri-n-octylphosphine oxide (TPO) are compared with triphenylmethane (TPM)-octane as the reference solution. In the range 0-0.2 m the results show deviations up to 10 and 20％ from ideal solution behavior of DPA dimer and TPO monomer, respectively. While partial trimerization of DPA (in qualitative agreement with previous iron(III) extraction results for DPA) and partial dimerization of TPO (which is not supported by molar polarization results) can account in part for the results, it is evident that nonspecific nonideal behavior of the solutes is also involved.