LAUSR

Abstract Critical temperatures and pressures were measured for five binary mixtures (DMC + n–hexane, DMC + n–heptane, DMC + n–octane, DMC + n–nonane and DMC + n–decane) and two ternary mixtures (DMC + n–hexane + n–octane and DMC + n–heptane + n–decane) covering whole composition interval. The critical properties were obtained from observing the critical opalescence. The standard uncertainties of temperatures and pressures are no more than 0.65 K and 0.016 MPa. The critical temperature and pressure curves of binary mixtures are continuous, belong to type I or type II defined by Scott and van Konynenburg. DMC + Alkane (n–heptane, n–octane and n–nonane) mixtures show minimums in critical temperature curve. The Redlich–Kister equations are used to correlate the critical properties for binary mixtures. The critical data for ternary mixtures are correlated with the Cibulka’s equations and Singh’s equations.