Excess heat capacities and excess molar enthalpies of the mixtures containing tetrahydropyran, piperidine and cyclic alkanones

Abstract

In the present study, molar heat capacities, $\left( {C_{\text{P}}^{{}} } \right)_{123}$, at T/K = 293.15–308.15 K with 5 K interval and excess molar enthalpies, $H_{ 1 2 3}^{\text{E}}$, at T/K = 308.15 for ternary tetrahydropyran (1) + piperidine (2) + cyclohexanone or cycloheptanone (3) and molar heat capacities, $(C_{\text{P}}^{{}} )_{12}$, for binary tetrahydropyran (1) + piperidine (2) mixture at T/K = 293.15, 298.15, 303.15 and 308.15 have been determined as a function of composition using microdifferential scanning calorimeter. The $\left( {C_{\text{P}}^{\text{E}} } \right)_{123}$, $H_{123}^{\text{E}}$ and $(C_{\text{P}}^{\text{E}} )_{12}$ data have been fitted to Redlich–Kister equation to predict ternary and binary adjustable parameters along with standard deviation in the measured properties. The observed $\left( {C_{\text{P}}^{\text{E}} } \right)_{123}$, $H_{123}^{\text{E}}$ data have been tested in terms of graph theory which in turns deals with the topology of the constituent molecules. It has been observed that $\left( {C_{\text{P}}^{\text{E}} } \right)_{123}$ and $H_{123}^{\text{E}}$ values estimated by graph theory are comparable with the experimental data.