Activation parameters of viscous flow for concentrated water-potassium thiocyanate solutions between 288 and 308 K

Abstract

Viscosity and density data of H₂O + KSCN system are reported in the concentration range 0.1-5.3 mol kg^-1 at 288.15, 298.15 and 308.15 K. The thermodynamic parameters <img src='http://www.niscair.res.in/jinfo/delta.gif' border=0><em>H*</em>, <img src='http://www.niscair.res.in/jinfo/delta.gif' border=0><em>S* </em>and <img src='http://www.niscair.res.in/jinfo/delta.gif' border=0><em>G* </em>of activation for viscous flow, calculated using Goldsack and Franchetto [<em>Can J Chem, </em>55 (1977) 1062.], Arrhenius, and Eyring equations, are also reported. Results have been discussed in the light of possible structural modification properties of KSCN. It is concluded that KSCN acts as a structure breaker over the studied concentration and temperature ranges. Though ion-solvent interactions are predominant upto <em>m</em>_min and lead to fall off in viscosity, increased ion-association with increasing concentration causes the increase in viscosity beyond <em>m</em>_min.