Viscosity and conductivity of aqueous solutions of some complex cyanides between 15° and 45°C

Abstract

The viscosity and conductivity of aqueous solutions of K [Ag(CN)₂], K₂ [Zn(CN)₄], K₂[Cd(CN)₄], K₂[Ni(CN)₄], K₃[CO(CN)₆], K₃[Fe(CN)₆], K₄[Fe(CN)₆] and K₄[Mo(CN)₈] were measured at 15, 25, 35 and 45°C in the concentration range 0.001-05 mol dm^-3. The viscosity results were fitted to an extended Jones-Dole equation                              η_r = 1 + Ac^1/2 + Bc + Dc² and the parameters A, B and D were evaluated. Theoretical values of A were calculated from the conductivity measurements. The B coefficients indicated that the complex anions are similar in behaviour to simple structure-breaking ions (e.g. K⁺, Cs⁺, Cl^-, Br^-), although they are of greater size and mostly multiply charged. Several specificities in behaviour, probably due to differing coordination geometry, were noted.