068 



The lines of demarcation between these planes: EP^, FP^, GP^, 

 HP^ and P^P^ indicate the solutions which are in equilibrium with 

 two solid salts, and the points P, and P.^ the solutions saturated 

 with three solid salts. 



We notice there are no solutions saturated with both KCl and 

 NaNOg. This pair of salts is, therefore the imstnbh' pair. If to a 

 solid mixture of these salts we add a little water a solution will 

 form in which one of the salts disappears and solid KNO^, solid 

 NaCl or both tliese solid phases are formed. 



NaCl and KNO3 are the stahle pair and the line l\P.i indicates 

 the solutions saturated with these salts. 



The point P, which represents the solution saturated with the 

 three solid salts NaCl. NaNO, and KNO, lies entirely within the 

 triangle, whose points indicate the com|)Osition of these salts. The 

 solution is, therefore "congruent-saturated". /\ lies just on the diagonal 

 NaCl — KNO,. Hence, this solution is still just "congruent-saturated". 



The equilibrium at 5°, 50°, and 100°. 

 The result of the determinations at these temperatures is contained 

 in the tables 2, 3, and 4. In tig. 2 these equilibria are represented 

 graphically. 



TABLE 2. Solubility at 5° C. 



