igo Conductivity of Aqueous Solutions. Part VI. 



(3) The degree of ionization of ammonium hydroxide increases 

 slightly between 18 and 51, but above 51 it decreases rapidly, as in 

 the case of all other substances thus far investigated. Thus the values 

 of its ionization-constant multiplied by 10 6 is 17.2 at 18, 18.1 at 51, 

 13.5 at 100, and 6.3 at 156. The mass-action law expresses the change 

 with the concentration at all temperatures. 



(4) The hydrolysis of ammonium acetate which is about 0.4 per cent 

 at 18, was found to be about 4.8 per cent at 100 and about 18 per cent 

 at 156, and to vary only slightly with the concentration of the salt, as 

 the mass-action requires in the case of a salt of this type. 



(5) The ionization-constant of water (that is, the product of the 

 concentrations of the hydrogen and hydroxide ions in it) which has been 

 previously found by Kohlrausch and Heydweiller to be 0.6 X 10~ 14 at 

 18, is 48 X 10- 14 at 100, and 223 X 10" 14 at 156, as deduced from the 

 hydrolysis of ammonium acetate. This great increase combined with 

 the decrease in ionization of weak acids and bases produces at high tem- 

 peratures an enormous increase in the tendency of salts to hydrolyze. 



