DETERMINATION OF STANDARD ENTHALPIES OF VAPORIZATION AND SUBLIMATION OF THREE DICHLOROBENZENES

By using an LEB 8721-3 vaporization calorimeter, enthalpies of vaporization of o- and m-dichlorobenzenes and enthalpy of sublimation of p-dichlorobenzene at 298.15K were determined as 48.53 +/- 0.12, 47.40 +/- 0.08 and 55.15 + 0.20 kJ mol(-1) respectively. Data of Delta H-V degrees and Delta H-3 degrees for chlorobenzenes reported here and in literature and their normal boiling points, t(b) in degrees C, can fit following two linear equations: Delta H-V degrees (kJ mol(-1)) = 17.51 + 0.17269 t(b), Delta H-3 degrees (kJ mol(-1)) = 26.25 + 0.22349 t(b). From these equations other unknown values of Delta H-V degrees and Delta H-3 degrees chlorobenzenes have been estimated.