EXCESS-ENTHALPIES OF BINARY-MIXTURES OF METHANOL WITH HEPTANONE ISOMERS AT 298.15 AND 323.15 K

The excess molar enthalpies, H-m(E), for methanol + 2-heptanone, 3-hep tanone, and 4-heptanone have been measured as a function of mole fract ion at 298.15 and 323.15 K by means of an isothermal now calorimeter. Values for H-m(E) are endothermic with a maximum value occurring at a mole fraction close to 0.5. The temperature effect on the excess entha lpy values is important. Maximum values at 298.15 K range from 725 to 744 J.mol(-1). Maximum values at 323.15 K range from 908 to 955 J.mol( -1). The position of the ketone group has little effect on the measure d H-m(E).