Angelo De Giglio

Solute-Solvent interactions in water-rich mixtures. II. Ionic conductances in water-dimethylsulfoxide mixtures at 25°C

Conductances of sodium bromide, iodide, and perchlorate, potassium chloride, and tetraphenylboride (BPh4−) as well as triisoamyl-n-butylammonium iodide (i-Am3BuNI) have been measured in aqueous mixtures containing up to 20 mole percent dimethylsulfoxide (DMSO) at 25°C. Experimental data were analyzed by the 1965 Fuoss-Onsager-Skinner (FOS) equation. Single-ion limiting equivalent conductances were calculated by assuming that λ0 (i−Am3BuN+=λ0 (BPh4−). The variations of the limiting ionic Walden products are discussed on the basis of acid-base type interactions for cations, and on the basis of structural effects for anions.

Ionic conductances in water-sulfolane mixtures at 30°C

AbstractConductances of solutions of triisoamyl-n-butylammonium (iAm3BuN+) iodide and sodium tetraphenylboride, iodide, and bromide have been measured in water-sulfolane mixtures at 30°C. Experimental data were analyzed by the 1965 Fuoss-Onsager-Skinner equations. The limiting equivalent conductances of triisoamyl-n-butylammonium tetraphenylboride (iAm3BuNBPh4) in each solvent mixture were obtained by the equation

Ionic contributions to the viscosity B coefficients of the Jones–Dole equation. Part 5.—Acetonitrile

\Lambda _0 (iAm_3 BuNBPh_4 ) = \Lambda _0 ({\text{i}}Am_3 BuNI) + \Lambda _0 (NaBPh_4 ) - \Lambda _0 (NaI)

The conductance of tetrabutylammonium salts in water-sulfolane mixtures at 30°C

Limiting ionic equivalent conductances in water-sulfolane mixtures were calculated on the assumption thatι0(iAm3BuNBPh4)/2λ0(iAm3BuN+)=λ0(BPh-4). The variations of the limiting ionic Walden product with solvent composition are discussed with respect to current information concerning solvent structural effects and ion-solvent interaction.

Excess volumes of (bromobenzene + an n-alkane) at 298.15 K

Eighty-three samples of mineral water from four different wells in the same district were analysed for 23 parameters. Nineteen parameters were chosen for multivariate analysis. Principal components analysis provided a feature reduction to two or three dimensions without substantial loss of information. The data set is well separated into four clusters using hierarchical and non-hierarchical methods; samples from different wells are generally assigned to different clusters.

Ionic B coefficients in water at 30, 40 and 50 °C

The B coefficients of the Jones–Dole viscosity equation are a measure of the size of the ions and of the interaction between the ions and the solvent. The B coefficients have been determined for the electrolytes Bu4NBu4B, Bu4NBr, Bu4NI, Ph4PBr, Ph4PI, NaI and NaPh4B, and for the homologous series from Et4NBr to Hept4NBr in acetonitrile at 25 and 35 °C. Ionic B values for the bromide and iodide ions have been calculated from the B coefficients for the tetra-alkylammonium solutions and are compared with those obtained from the tetraphenylphosphonium solutions. The transition-state treatment has been applied to the results, and the thermodynamic activation parameters for viscous flow have been calculated. These are compared with those found previously for solutions of dimethyl sulphoxide, hexamethylphosphoric triamide and N,N-dimethylformamide, and are discussed in terms of the new theory of B coefficients proposed by Feakins.

Ion–solvent interactions in water-rich binary mixtures. Part 2.—Viscometric behaviour of NaCl, NaBr, KCl, KBr and Bu4NBr in water + hexamethylphosphoric triamide mixtures at 25 and 35 °C

Abstract Molar excess heat capacities at constant pressure, C E p , of binary liquid mixtures chloroform + oxolane, chloroform + 1,3-dioxolane, chloroform + oxane, and chloroform + 1,4-dioxane have been determined at 298.15 K from measurements of volumetric heat capacities in a Picker flow microcalorimeter. A precision of ±0.04 J K −1 mole − was achieved by using the stepwise procedure. Experimental molar excess heat capacities are compared with values derived from H E results at different temperatures. Excess molar volumes, V E , for the same systems at 298.15 K have been determined by measuring the density of the pure liquids and solutions with a high-precision digital flow densimeter.

Enthalpies of solution of tetra-alkylammonium salts in hexamethylphosphotriamide at 298.15 K

Conductance measurements are reported for Bu4NCl, Bu4NBr, Bu4NI, and Bu4NClO4 at 30°C in water-sulfolane mixtures over the entire solvent composition range. Experimental data were analyzed by the 1965 Fuoss-Onsager-Skinner equation. The limiting equivalent conductances in water and in sulfolane were compared with literature values. The trends of the Walden products are discussed in terms of water structural changes caused by addition of sulfolane. As expected, on the basis of previous results reported in the literature, a significant amount of association was detected for Bu4NI in water. Very small association constants were also found for Bu4NI and Bu4NClO4 at 10 wt.% sulfolane.