107U 



Ncr/STO, 



KNO^ 



c 



B 



Na.Ci O-^ ^'^ °'^ °'^ ^-5 o,ö oj qs o,g j^Ci 



Fis. ± 



The general chiiracter of tlie eqiiilibiiiiiii line is not influenced by 

 the change in leinpeiatiii-e. It appears, however, that at an elevation 

 of temperature the region of NaCl becomes much laj:ger and that 

 of KNO3 and NaNO, much smaller. Hence, /^ and P., shift considerably 

 upwards. 



Pj always remains congruent saturated, P^ is so also at 5°; at 

 50° and 100°, however it lies outside the triangle NaCl, KCI, KNO3 

 and the solution is no longer congruent saturated. A solution is 

 formed with separation of solid KCI when NaCl and KNO, are 

 treated with water. 



It further appears that at all temperatures the solubility of NaNOj 

 (per 100 grams of water) is not lowered by addition of KNO3, 

 as might be expected from a salt with a homonymous ion on the 

 ground of the theory of electrolytic dissociation, but increased. At a 

 high temperature this behaviour is comprehensible, if we considei 

 that the eutecticum of the system NaNO, — KNO, lies at 218°. The 

 solubility of the eutectic mixture (49 mol. 7^ NaNO, to 51 mol. "/o 

 KNO3) is then = oo whereas Hie solubility of NaNOs and KNO3 at 

 the temperature of 218° will still have definite values. As this 



