Excess enthalpies and excess volumes of (1-bromobutane or 1-iodobutane + 1-chloropropane or 1-chloropentane) and of (1-iodobutane + bromoethane or 1-bromobutane) at the temperature 298.15 K

Abstract

The excess enthalpies HEm and excess molar volumes VEm of [x{CH3(CH2)3Br or CH3(CH2)3I} + (1 - x ){CH3(CH2)2Cl or CH3(CH2)4Cl}] and of [xCH3(CH2)3I + (1 - x ){CH3CH2Br or CH3(CH2)3Br}] have been measured at the temperature 298.15 K. Mixing was endothermic at all x and the HEmS were found to vary in the sequence: (1-iodoalkane + 1-chloroalkane) > (1-iodoalkane + 1-bromoalkane) > (1-bromoalkane + 1-chloroalkane). A plausible explanation is that the specific-interaction energies lie in the sequence: I-Cl > I-Br > Br-Cl. On the contrary, not all the VEmS are positive. For {xCH3(CH2)3I + (1 - x ){CH3CH2Br or CH3(CH2)2Cl} and for {xCH3(CH2)3Br + (1 - x )CH3(CH2)2Cl} the VEmS are negative for all x.