Relative viscosities of alkali halide solutions in formamide

Abstract

Measurements of the viscosity of electrolyte solutions in formamide, HCONH₂, have been made on a representative group of alkali metal halides, over a range of temperatures. A self-consistent set of viscosity B-coefficients has been derived. Methods of partition of the latter into ionic components are discussed. Consideration of temperature coefficients of the B-values and solute activation parameters leads to the conclusion that cations enhance the formamide structure in the order: Na⁺ > Li⁺ > K⁺ Rb⁺ > Cs⁺. The anions Cl^– and Br^– show neither definite structure-making nor structure-disrupting behaviour, while the I^– ion may have a very weak structure-breaking effect.