Conductance of Some Higher Homologues of Quaternary Ammonium Bromide Salts in 2-Butoxyethanol (1) + Water (2) Mixtures at 298.15, 303.15, 308.15, and 313.15 K.

Conductance data of some higher homologues of quaternary ammonium salts, namely, tetrapentylammonium bromide (Pen4NBr), tetrahexylammonium bromide (Hex4NBr), and tetraheptylammonium bromide (Hep4NBr) in 2-butoxyethanol (1) + water (2) mixture with 0.20, 0.40 and 0.60 mass fraction of 2-butoxyethanol were reported at 298.15, 303.15, 308.15, and 313.15 K. The 1978 Fuoss conductance-concentration equation was used to analyze the measured experimental conductance data. The values of limiting molar conductance ( Λ 0 ), ionic association constant (KA) and the association diameter (R) were obtained from the analysis. The ionic contributions to the limiting molar conductances were estimated using tetrabutylammonium tetraphenylborate (Bu4NBPh4) as the "reference electrolyte". A weak electrostatic ion solvent interaction was observed for these three salts from their calculated KA and R values. The study also revealed that in all solvent compositions and experimental temperatures, these salts exist as free ions. The association constants of the electrolytes do not vary significantly as a function of temperature. However, as the temperature was increased or solvent compositions were changed, a noticeable variation in the single-ion conductivity values as well as Walden product for the ions were seen. [ABSTRACT FROM AUTHOR]