Thermodynamic Properties of Ternary Ionic Liquid Mixture Containing a Common Ion: Excess Molar Volumes,Excess Isentropic Compressibilities,Excess Molar Enthalpies and Excess Heat Capacities

In the present investigations, the excess molar volumes, ( V_{ijk}^{text{E}} ), excess isentropic compressibilities, ( left( {kappa_{S}^{text{E}} } right)_{ijk} ), and excess heat capacities, ( left( {C_{p}^{text{E}} } right)_{ijk} ), for ternary 1-butyl-2,3-dimethylimidazolium tetrafluoroborate (i) + 1-butyl-3-methylimidazolium tetrafluoroborate (j) + 1-ethyl-3-methylimidazolium tetrafluoroborate (k) mixture at (293.15, 298.15, 303.15 and 308.15) K and excess molar enthalpies, ( left( {H^{text{E}} } right)_{ijk} ), of the same mixture at 298.15 K have been determined over entire composition range of x _i and x _j . Satisfactorily corrections for the excess properties ( V_{ijk}^{text{E}} ), ( left( {kappa_{S}^{text{E}} } right)_{ijk} ), ( left( {H^{text{E}} } right)_{ijk} ) and ( left( {C_{p}^{text{E}} } right)_{ijk} ) have been obtained by fitting with the Redlich–Kister equation, and ternary adjustable parameters along with standard errors have also been estimated. The ( V_{ijk}^{text{E}} ), ( left( {kappa_{S}^{text{E}} } right)_{ijk} ), ( left( {H^{text{E}} } right)_{ijk} ) and ( left( {C_{p}^{text{E}} } right)_{ijk} ) data have been further analyzed in terms of Graph Theory that deals with the topology of the molecules. It has also been observed that Graph Theory describes well ( V_{ijk}^{text{E}} ), ( left( {kappa_{S}^{text{E}} } right)_{ijk} ), ( left( {H^{text{E}} } right)_{ijk} ) and ( left( {C_{p}^{text{E}} } right)_{ijk} ) values of the ternary mixture comprised of ionic liquids.