Topological Investigations of Excess Heat Capacities of Binary and Ternary Liquid Mixtures Containing o-Chlorotoluene, Amides and Cyclohexane at 298.15, 303.15 and 308.15 K

Excess heat capacities, and , of binary tetrahydropyran (1) + N-methylformamide or N,N-dimethylformamide or cyclohexane (2), o-chlorotoluene (1) + cyclohexane (2), and ternary o-chlorotoluene (1) + tetrahydropyran (2) + N-methylformamide or N,N-dimethylformamide or cyclohexane (3) mixtures have been determined from their measured heat capacities, and , at 298.15, 303.15 and 308.15 K. The and values have been correlated using the Redlich-Kister equation to show their dependence on composition. The excess heat capacities, , give information about the degree of non-randomness in the mixture. In this context, non-randomness contributes positively to whereas randomness results in negative values. The connectivity parameters of third degree, (3) xi, of the constituent molecules, which in turn deal with topology, have been utilized (Graph theory) to compute and values of the investigated mixtures. The experimental and values compare well with those calculated from Graph theory. The excess heat capacities, and of binary and ternary mixtures have also been analyzed in terms of Flory's theory.