Molar Excess Volumes of Ternary Mixtures Containing a Cyclic Ether

Molar excess volumes, VijkE, of 1,3-dioxolane or 1,4-dioxane (i) + water (j) + formamide or dimethylformamide (k) ternary mixtures have been determined dilatometrically over the entire composition range at 308.15 K. The measured data have been analyzed in terms of (a) the graph theoretical approach, (b) the Lacombe and Sanchez theory, and (c) the Flory theory. It was observed that VijkE values predicted by graph theory compare well with their corresponding experimental values. However, VijkE values evaluated by the Lacombe and Sanchez as well as the Flory theory are of same sign and order.