journal of kerbala university

Densities ρ and viscosities η of cysteine (Cys) in 2.5% and 5%(w/w) Dimethylformamide (DMf)-water mixtures have been measured at different temperatures 298.15, 303.15, 308.15 and 313.15 K. From the experimental data molal volume , limiting partial molal volume , the slop , Jones-Dole B and D-coefficients, Gibbs free energy of activation for viscous flow of solution were calculated. The nature of solute- solvent and solute- solute interactions have been discussed in terms of the values of , , and B-coefficient.