Densities, Viscosities [from (278.15 to 318.15) K], and Electrical Conductivities (at 298.15 K) of Aqueous Solutions of Choline Chloride and Chloro-Choline Chloride

Data for the electrical conductivity (at 298.15 K), density, and viscosity [both at (278.15, 288.15, 298.15, 308.15, and 318.15) K] of aqueous solutions of choline chloride (ChCl) and chloro-choline chloride (Cl-ChCl) are reported for solute molalities m ≲ 2.0 mol·kg –1 (ChCl) and ≲ 2.1 mol·kg –1 (Cl-ChCl), respectively. From the densities apparent molar volumes were calculated, and the limiting partial molar volumes and Hepler's constants of ChCl(aq) and Cl-ChCl(aq) were evaluated. From the viscosities Arrhenius activation energies of viscous flow were determined. While apparent molar volumes suggest at best weak ion pairing for ChCl(aq) and Cl-ChCl(aq), the Walden product obtained for 25 °C hints at significant ion–ion interactions and/or changes in ion hydration with increasing concentration.