Abstract
Abstract A review of publications on stability of mechanical equilibrium of multicomponent mixtures in gases and liquids under non‐isothermal and isothermal conditions is given. Studies where diffusion in binary and multicomponent mixtures led to the occurrence of instability of mechanical equilibrium of the system have been analyzed. The main attention is paid to the description of approaches predicting the areas where there are increasing convective disturbances, as well as the determination of the spectrum of thermophysical parameters where the contribution of convection to heat and mass transfer is negligible. At the same time, the problems determining the role of diffusion, thermodiffusion, and double diffusion mechanisms in the separation of mixture components at the boundary of convective instability were given priority in the description. The results of investigations related to the study of the evolution of flows arising due to instability at the initial stage of mixing were also discussed.