The two phases were considered in the field Temperature - Pressure at physical model, gas and liquid distributed the equilibrium. Thermodynamics characteristics were graphed from zero for every substance separately: gas and liquid. Bibliography data were used to calculate Dew point curve. There were confirmed critical point lays on DewP curve here. Rate of each phase is equal 0.5 on DewP curve. Boil curve was graphed also. There are several boiling points at P=1 atm. It was explained that fenomena several temperature boiling points at atmosphere pressure.