Thermodynamic behaviour of the eight systems containing pentan-3-one and a chloroalkane, namely 1-chlorobutane, 1,2-dichloroethane, 1,3-dichloropropane, 1,4-dichlorobutane, trichloromethane, 1,1,1-trichloroethane, tetrachloromethane and 1,1,2,2-tetrachloro- ethane was interpreted in terms of the DISQUAC group contribution model. It was found that quasichemical term for the contact C=O/Cl in the pentan-3-one-α,ω-dichloroalkane and pentan-3-one-1,1,1-trichloroethane systems is not negligible. The DISQUAC dispersive interchange parameters for C=O/Cl contact in these systems were evaluated from literature data on linear ketone + 1-chloroalkane systems. It was found that the best description of experimental data for systems containing 1-chlorobutane, trichloromethane, tetrachloromethane, and 1,1,2,2-tetrachloroethane is provided using only dispersive contribution of the C=O/Cl contact. The vapour-liquid equilibrium, GE, and HE data were calculated using the DISQUAC model and compared with experimental data. The model provides a fairly consistent description. The relation between the DISQUAC interchange parameters for C=O/Cl contact and the chloroalkane chain length was established.
