The psuedo ternary LLE data are reported for the following systems at 298.15 K: an aqueous sulfuric acid solution (ASS) + dodecane + tributylphosphate (TBP); an ASS + 1-dodecanol + TBP; an ASS + undecane + TBP; an ASS + dodecane + trioctylamine (TOA); an ASS + 1-dodecanol + TOA and an ASS + undecane + TOA. These experimental LLE data were correlated well with the non-random two-liquid (NRTL) G(E) model. In addition, the density (rho) and the refractive index (n(D)) for the systems {TBP + dodecane}, {TBP + 1-dodecanol}, {TBP + undecane}, {TOA + dodecane}, {TOA + 1-dodecanol} and {TOA + undecane} at 298.15 K were determined. These data were used to calculate the binary excess molar volumes (V-E) and the deviations of the refractive indices (Delta R) over the entire composition range. The experimental data were satisfactorily fitted using the Redlich-Kister polynomial. (c) 2013 Elsevier B.V. All rights reserved.