Excess heat capacities of 1-methyl pyrrolidin-2-one and pyridine or picolines mixtures

•The CPE data of the studied mixtures have been measured at 293.15, 298.15 and 303.15 K.•The measured CPE data have been fitted to Redlich–Kister equation.•The observed CPE values have been analyzed in terms of Graph theory.•The CPE values calculated by Graph theory compare well with experimental values.

The excess heat capacities, CPE, of binary 1-methyl pyrrolidin-2-one (i) + pyridine or α- or β- or γ-picoline (j) mixtures have been measured as a function of composition at 293.15, 298.15 and 303.15 K using micro differential scanning calorimeter (Model – μDSC 7 Evo). The CPE data have been fitted to Redlich–Kister equation to calculate binary adjustable parameters and standard deviations. The measured property of the studied mixtures has been analyzed in terms of Graph (which deals with the topology of the constituent of mixtures) theory. It has been observed that Graph theory describes well the CPE data of the investigated binary mixtures.