In this work we analyzed models for the balance of liquid vapor equilibrium binary solutions. To determine the activity coefficient of binary mixtures, we used the Margules model. For 10 different binary aqueous solutions, the concentration, pressure and temperature equilibrium diagrams were drawn. An analysis of the methods for determining the heat transfer coefficient and critical heat flux of binary aqueous mixtures was carried out. In calculating the heat transfer coefficient, the most useful results for alcoholic aqueous solutions are given by Thome's model.