Ionic Association and Conductances of Some Symmetrical Tetraalkylammonium Salts in Methanol, Acetonitrile, and Methanol (1) + Acetonitrile (2) Mixtures at 298.15 K

Electrical conductance measurements are reported for tetrahexylammonium bromide (Hex 4 NBr), tetraheptylammonium bromide (Hep 4 NBr), and tetrabutylammonium tetraphenylborate (Bu 4 NPh 4 B) in methanol, acetonitrile, and methanol (1) + acetonitrile (2) binary mixtures at 298.15 K. The conductance data have been analyzed by the Fuoss conductance−concentration equation in terms of the limiting molar conductance (Λ°), the association constant ( K A ), and the distance of closest approach of ions ( R ). Single-ion conductivities have been determined on the basis of tetrabutylammonium tetraphenylborate as the reference electrolyte. The results have been interpreted in terms of ion−ion and ion−solvent interactions.