The Heats of Mixing for Binary Mixtures. III. The Intermolecular Energy of Hydrogen Bonding between Alcohol and Several Other Polar Molecules

Abstract

Abstract Calorimetric measurements of the heat of mixing have been made at 25.0±0.01°C for binary mixtures of n-butanol with polar liquids (acetonitrile, acetone, n-butyl ether, and n-butyl amine), and for binary mixtures of polar liquids with n-hexane. The calorimeter for measuring the heats of mixing was of twin type, and a thermomodule, HTM 0516 type (Sharp Electric Co., Ltd., Osaka) was used as the temperature-sensing device. By plotting the values of the heat of mixing, ΔHx1m, against the mole fraction of component 1, x1, and by extrapolating the curve to an infinite dilution (x1→0) for each system, the heats of mixing per mole of component 1 at an infinite dilution (\undersetx1→0limΔHx1m) were obtained graphically. By using the values of \undersetx1→0limΔHx1m obtained for these systems and by using the same treatment as that described in a previous paper [S. Murakami, K. Amaya and R. Fujishiro, This Bulltein, 37, 1776(1964)], the intermolecular hydrogen bond energies between alcohol and polar molecules were estimated; it was found that the strength of the hydrogen bond was in the following order: n-butyl amine>n-butyl ether>acetone>acetonitrile. This agrees with the results obtained from the spectroscopic study.