Excess molar enthalpies of mixing of 1-butanol with aromatic hydrocarbons at 308.15 K

1063-1069Molar excess enthalpies, HE, of mixing data for 1-butanol with benzene, toluene and o- m- and p-xylenes at 308.15 K over the entire range of composition have been reported. HE values for all the present binary mixtures are positive and HE versus mole fraction curves are slightly skewed towards the low mole fraction of 1-butanol, x1 having HE (max) at x1=0.3S. Qualitatively, the data show the dissociation of self associated 1-butanol molecules through hydrogen bonding with the addition of aromatic hydrocarbons. Further there are electron- donor acceptor interaction between the p - electrons of aromatic ring and the hydroxyl hydrogen. of 1- butanol. Quantitatively, the data have been analysed in terms of the Mecke-Kempter type association model with a Flory contribution term by estimating association parameters like standard enthalpy, entropy and volume of H-bond formation