ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Computational Problems in Evaluation of Colligative Property Equilibrium Data

M. Martinez, N. Miralles, A. Sastre, M. Lubalova, and J. Havel

Departament d'Enginyeria Quimica, Universität Politécnica de Catalunya E.T.S.E.I.B. Diagonal, 647, E-08028 Barcelona, Spain

Abstract: Computational problems in evaluation of colligative property data are discussed. Especially, the problem of the determination of the calibration constants is analyzed. Calibration constants may be determined either using reference substances or simultaneously with the aggregation constants of the compounds studied. However, calibration constants should be considered as ''danger'' parameters and experimental determination is highly recommended.The aggregation equilibria of bis(2-ethylhexyl)monothiophosphoric acid (DEHTPA) and trioctylmethylammonium chloride (TOMACl) dissolved in toluene were investigated by vapour pressure osmometry. The experimental data were treated numerically by the program CPLET and the average aggregation number (n) over bar of the extractants, as well as the aggregation constants were determined. It was found that DEHTPA exists in toluene as an equilibrium mixture monomer-dimer-dodecamer and TOMACl as monomer, trimer, and tetramer species, respectively.

Full paper in Portable Document Format: 503a109.pdf

Chemical Papers 50 (3) 109–114 (1996)