Excess molar enthalpies for [Bmmim][BF4] + [Bmim][BF4] or [Emim][BF4] + cyclopentanone or cyclohexanone mixtures

In recent years, studies on mixtures consisting of ionic liquids and organic solvents have gained importance for the application of such mixtures for new chemical processes and technologies in industries. In this contribution, new experimental excess molar enthalpies, \( H_{\text{ijk}}^{\text{E}} \) data of ternary 1-butyl-2,3-dimethylimidazolium tetrafluoroborate, [Bmmim][BF4] (i) + 1-butyl-3-methylimidazolium tetrafluoroborate, [Bmim][BF4] or 1-ethyl-3-methylimidazolium tetrafluoroborate, [Emim][BF4] (j) + cyclopentanone (CPO) or cyclohexanone (CHO) (k) mixtures, have been reported over the whole composition range at 298.15 K and atmospheric pressure. The observed data have been satisfactorily correlated by Redlich–Kister equation for each mixture. The \( H_{\text{ijk}}^{\text{E}} \) values for [Bmmim][BF4] (i) + [Bmim][BF4] or [Emim][BF4] (j) + CPO (k) mixtures are positive over whole range of composition of xi and xj. The sign and magnitude of \( H_{\text{ijk}}^{\text{E}} \) values for [Bmmim][BF4] (i) + [Bmim][BF4] or [Emim][BF4] (j) + CHO (k) mixtures vary with the change in composition of the components of the mixtures. The \( H_{\text{ijk}}^{\text{E}} \) data have also been analyzed in terms of graph theory (which involves the topology of the molecule). It has been observed that estimated values by graph theory compare well with their corresponding experimental values.