EXCESS-ENTHALPIES AND EXCESS VOLUMES OF MIXING FOR MIXTURES OF ISOMERIC BUTYL AMINES AND ACETONITRILE

The excess enthalpies and excess volumes of 1-aminobutane, 1-amino-2-m ethylpropane, 2-aminobutane and 2-amino-2-methylpropane with acetonitr ile were determined at 303.15 and 298.15 K, respectively, using a micr ocalorimeter and a densimeter. Dissociation of self-associated amine s pecies and formation of amine-acetonitrile complexes were expected to take place in solution. The excess enthalpies were positive and the ex cess volumes were negative for all four systems. The enthalpies of com plex formation were calculated from the partial molar enthalpies. The endothermic heats of mixing and negative volume change on mixing are e xplained in terms of the extent of formation of amine-acetonitrile com plexes in the liquid mixtures.