Physico-chemical properties of NH4I-formamide concentrated solutions

Density, viscosity and electrical conductivity of NH₄I-formamide solutions up to the saturated concentration, in the temperature range 25–55°C, are reported in this work. From the density data which linearly depend on the salt concentration, apparent and partial molar volumes constant and close to the molecular volume of pure salt can be deduced. Viscosity data, treated following the V and model, show a weak interaction of NH⁺₄ ion with the solvent in all the range of concentrations used. Viscosity and conductivity have also been analysed, following a proposal of Angell, with an extended Arrhenius equation used in the treatment of transport in glass-forming liquid.