Viscosity B Coefficients for the Tetraalkylammonium Halides

In this paper we report enthalpies of solution at infinite dilution [Formula: see text] at 298.15 K for tetraphenylarsonium chloride (Ph4AsCl), sodium tetraphenylborate (NaBPh4), sodium chloride (NaCl), sodium bromide (NaBr), and sodium iodide (NaI) in water and aqueous solutions containing 5, 10, 20, and 30% urea by weight. Enthalpies of transfer from water to aqueous urea solutions are reported. Single-ion enthalpies of transfer [Formula: see text] have been calculated using the tetraphenylarsonium tetraphenylborate, (TATB) reference electrolyte assumption. These single-ion enthalpy data have been combined with single-ion Gibbs functions of transfer [Formula: see text] reported in the literature to obtain single-ion entropies of transfer [Formula: see text] for the urea + water mixed solvent system. The results of this single-ion analysis are discussed in terms of the impact of electrolytes on the structure of aqueous urea solutions.

Section: Discussionsupporting

confidence: 92%

Single-ion enthalpies and entropies of transfer from water to aqueous urea solutions at 298.15 K

Hakin¹,

Beswick²

1992

“…3 where (q/qo -1 -Ac'I2)/c is plotted against c (15). The B, and D, coefficients are obtained from this plot though, for the present discussion, only B, is used (Table 3).6 The A, coefficients required to subtract the effect of the long-range coulombic forces on the viscosity (24) were calculated from the conductance data (24,28,29 solutions, k0.1 cm3 mol-'; in methanol solutions, + 1 cm3 mol-' ; 4; in aqueous solutions,…”

Section: " 4mentioning

confidence: 99%

“…' Effective radii, such as r,, are usually a combined measure of the particle size and of the effect of the particle on the surrounding solvent (solute-solvent interactions and structural effects). Similarly, viscosity B, coefficients include both a size effect and a contribution arising from changes in the local viscosity around the solutes (24,38). Therefore, r, and B, should follow the same pattern in the series of ions studied here.…”

Section: (A) Efectice Ionic Sizesmentioning

confidence: 99%

A Comparative Study of Bu₄NBr, NaBPh₄, Ph₄PCl, and Ph₄AsCl in Water and Methanol at 25 °C: Partial Molal Volumes, Heat Capacities, and Viscosities

Jolicoeur¹,

Philip²,

Perron³

et al. 1972

The apparent molal volumes (4,) and heat capacities (4,) of Bu4NBr, NaBPh,, Ph,PCI, and Ph,AsCI have been measured in water and methanol at 25 "C in the concentration range 0.0 1-0.2 M. The viscosity of aqueous NaBPh, and Ph,AsCI have also been measured at 25 "C and in the same concentration range. Individual ionic values have been estimated for most of these properties. A comparison of these values for the quaternary ions Bu,N+, BPh;, Ph4P+, Ph,As+ illustrates sizable differences in the solute-solvent interactions of alkyl and aryl substituted ions. Some specificity is also suggested in the solvation of the tetraphenyl ions, as shown by a comparison of the properties which should reflect directly the size of the ions (rStokes, Po, and B,) and also in ( H 2 0 + CH30H) transfer functions.Le volume apparent molaire (4,) et la capacite calorifique apparente molaire (4,) de Bu,NBr, NaBPh,, Ph4PCI, et Ph,AsCI ont it6 mesurts dans I'eau et dans le methanol a 25 "C, dans un domaine de concentration variant de 0.01 a 0.2 M. Egalement, la viscosite de solutions aqueuses de NaBPh, et Ph,AsCI a eti determinee. Pour la majorite de ces proprietes, des valeurs ioniques individuelles ont pu Stre estimees. La comparaison de ces valeurs pour les differents ions quaternaires met en evidence une difference significative entre les interactions solute-solvant des ions quaternaires, selon que les substituants sont aliphatiques ou aromatiques. Dans la serie BPh;, Ph,P+, et Ph,As+, une certaine specificit6 dans la solvatation est egalement apparente, particulierement dans les proprietis qui refletent directement la dimension des ions (rStokes. p. et B,) et dans les fonctions thermodynamiques de transfert (H,O + CH30H).

“…Further, the K A values for all the salts in a given dielectric medium increases with increasing size of the ions in the dielectric range (71.40 2 D 2 28.70) in the order Me4N' < E4N' < Pr4N' < Bu4N' --Bu4P' as expected (23)(24)(25)(26)(27).…”

Section: Association Constant and Distance Parametermentioning

confidence: 63%

Conductimetric studies of ionic association of tetraalkylammonium halides in iso-propanol + water mixtures at 25 °C. Part II.

Ansari¹,

Islam²

1988

AIJAZ AHMAD ANSARI and M. R. ISLAM. Can. J. Chem. 66, 1720Chem. 66, (1988.Electrical conductivities of Me4NBr, Et4NBr, Pr4NBr, Bu4NBr, and Bu4PBr have been measured in isopropanol + water KA, and the distance of ion-size parameter (R or a;) are computed from these data. A better fit of the conductance data was provided by the F78 equation. Ion-solvent interactions and effective sizes of tetraalkylarnmonium ions are also discussed in order to understand the magnitude of the ionic association. The overall association behaviour of these salts has been found to increase with decrease in dielectric constant of the medium.