CONGRUENT MELTING OF BINARY COMPOUNDS WITH NONNEGLIGIBLE VAPOR-PRESSURE .2. APPLICATION TO THE SULFAGUANIDINE-WATER SYSTEM

The sulfaguanidine-water (SG-H2O) system is a binary system with non-n egligible vapour pressure which presents a monohydrate. The phase diag ram of this system is drawn from DTA experimental results, using the t emperature-specific volume-molar fraction (T-v-x) model which was desc ribed in part I of this work. The melting of the monohydrate (SG, H2O) is found to be congruent. Isochoric sections are drawn; they make it possible to determine the limits of the two eutectic invariant planes. The composition and specific volume of the vapour phase at the eutect ic equilibrium of the SG-SG, H2O subsystem are given. The triple line solid-liquid-vapour of the one-component phase diagram of the monohydr ate is drawn. The experimental results are consistent with the congrue nt melting of the monohydrate. These results also show that the solid, liquid and vapour phase at the triple line have not the same composit ion.