In this paper

the boiling points of methyltrichlorosilane-methylvinyldichlorosilane-toluene system and of the respective three binary systems are determined at 101.3 kPa with a new type of magnetical pump-ebulliometer. The VLE data of the three binary systems

are correlated with the Margules

van Laar

Wilson

and NRTL equations. The equilibrium composition of the vapor phase of three binary systems are calculated from Tpx by indirect method. Fugacity coefficients are calculated after accounting for the nonideality of the vapor phase

by using calculated virial coefficients. The model parameters of liquid activity coefficient are correlated by the least square method. The vapor pressure of the pure components are obtained by using Antoine constants from the literature. At the same time

the saturation vapor presure of methylvinyldichlorosilane is measured. The VLE data of ternary system are predicted by the Wilson equation. The calculated boiling points show good agreement with the experimental data.