Coexistence Curve for 3-Methylpentane–Nitroethane near the Critical Point

The coexistence curve for the liquid mixture 3-methylpentane–nitroethane has been obtained using a visual and a float technique. A detailed analysis of the data shows that the composition differences of the coexisting liquid phases are proportional to (tc — rpar;β, where β = 0.340 with a standard deviation of 0.010. As a result of this analysis and an analysis of the earlier work of Rice and Zimm it is shown that the value of β for binary liquids is not significantly different from the value for gas–liquid systems.