Excess molar enthalpies of several binary liquid mixtures containing either phenylmethylether (anisole) or benzaldehyde and an aromatic

For the 11 binary liquid systems [xC6H5OCH3 + (1 - x){C6H6, or C6H5CH3, or 1,2-C6H4(CH3)2, or 1,3-C6H4(CH3)2, or 1,4-C6H4(CH3)2, or C6H5C2H5, or 1,2,4-C6H3(CH3)3, or 1,3,5-C6H3(CH3)3, or C6H5CH(CH3)2}] and [xC6H5CHO+ (1 - x){C6H5C2H5, or 1,3,5-C6H3(CH3)3}], excess molar enthalpies HE have been measured as a function of mole fraction x of either phenylmethylether (PME, anisole, methoxybenzene, C6H5OCH3) or benzaldehyde (BA, C6H5CHO) at the temperature T = 298.15 K and atmospheric pressure. For these measurements, an LKB differential flow microcalorimeter equipped with two computer-controlled h.p.l.c. piston pumps (from Gilson) was used. For the mixtures of PME with an aromatic, the HE-curves are all positive and rather small, and more or less parabolic; {PME + 1, 3, 5-trimethylbenzene (mesitylene)} exhibits the largest values: HE (x = 0.5) = 358 J mol-1. The excess molar enthalpies of the mixtures of benzaldehyde with an aromatic are also all positive and rather small [e.g., for (BA + 1, 3, 5-trimethylbenzene) HE (x = 0.5) = 316 J mol-1], though somewhat more skewed than those of the corresponding mixtures with PME. Π2002 Elsevier Science B.V. All rights reserved.