Ternary vapour-liquid equilibria system: Acetoneethyl methyl ketone-cyclohexane

Experimental T‐x‐y data of the system: acetone‐ethyl methyl ketone‐cyclohexane at 760 mm. Hg pressure are reported. The data were obtained using a modified Colburn type of equilibrium still. No ternary azeotrope was observed. The experimental data were found to be thermodynamically consistent according to the method of Krishnamurty & Venkata Rao which is based on the Gibbs‐Duhem equation. The activity coefficient data of the present system have been satisfactorily correlated with the modified Margules equations developed earlier, using a ternary constant Ct = 0·5. In the case of the present system, the modified Margules equations with Ct = 0·5 are equivalent to the three‐suffix ternary Margules equations of Wohl, with C = 0·305. The ternary smoothed experimental T‐x‐y data are compared with the data calculated using the modified Margules equations with Ct = 0·5 and there is close agreement between the calculated and experimental data. It is suggested that the thermodynamic consistency test proposed by Krishnamurty & Venkata Rao and the modified Margules equations may be used together for mathematical analysis of the ternary vapour‐liquid equilibrium data since the same smoothed experimental log γi/γj values can be used for both the methods.