Phase Equilibrium of the Nitrogen-Hydrogen System in the Critical Region of Hydrogen

Abstract

In the experiments on the solid-gas equilibrium of the nitrogen-hydrogen system we approached the three-phase line from the high pressure region along the gas boundary. The lower critical end point B (see Fig. 1) is not far from the critical point C₂ of pure hydrogen, which means that the pressure corresponding to this state is of the order of 13 atm. In Fig. 2 the three-phase equilibrium is given by the line dgc where g represents the liquid phase which contains more dissolved nitrogen than the gaseous phase shown by point c. Solid nitrogen which is supposed to be pure is given by point d.