Electroconduction, Association, and Ion–Molecular Interactions in Nickel Chloride Solutions in Methanol at 5–55°C

Abstract

Results of a conductimetric investigation of nickel chloride in methanol at 5–55°C and electrolyte concentrations of 0.1–5 mM are presented. Limiting equivalent conductivities by Ni2+ and Cl− and constants of ionic association in the first step with the formation of ionic pair NiCl+ are determined for asymmetric electrolytes using an extended Lee–Wheaton equation. In dilute nickel chloride solutions in methanol the association of ions in the second step is inessential. The size of dynamic solvation sheaths of the ions and the short-range non-coulombic interion potential suggest that the Ni2+ ion forms a kinetically and energetically stable solvated complex with the nearest solvation layer being ∼400 pm thick and virtually temperature-independent. The nearest kinetically stable solvation sheath of the Cl− ion comprises mostly hydroxyl groups of methanol molecules and its stability is severely dependent on temperature.