  Evaporation of liquid into a vapor-gas mixture is interesting and important
process as for fundamental research and for different applications. In general,
the rate at which a liquid evaporates is dependent on the transport of mass and
energy occurring within both the liquid and vapor phases. This study is carried
out on the base of continuum conservation equations for two-component medium.
At the beginning the stability conditions for mechanical equilibrium are
deduced. This paper is devoted to this theme.
