Hydrogen Ion Concentration of Acid Solutions. 5 



Table II. 



Effect of Salts upon the Concentration of Hydrogen Ion of o.i Normal 



Hydrochloric Acid. 



Cone. Salt. Log. Ch+- 



Cone. Salt. 



Log. C H +. 



Sodium Chloride. Potassium Chloride. 



0 



1 Molar 



2 " 



3 " 



4 " 



- 1.038 



- 0.88 



- 0.72 



- 0.52 



- 0.36 



1 Molar 



2 " 



3 " 



4 ' " 



- I.038 



- 0.95 



- O.85 



- 0.75 



- O.63 



Ammonium Chloride. Lithium Chloride. 



0 



3 M 



4 ■ 



- 1.038 



- 0.94 



- 0.87 



- 0.75 



- 0.65 



0 



1 Molar 



2 " 



3 " 



4 " 



— I.038 



— 0.81 



— 0.60 



— 0.35 



— 0.12 



Barium Chloride. Magnesium Chloride. 



0.25 Molar 



0.5 " 



0.75 " 



— 1.038 



— 0.96 



— 0.88 



— 0.80 



— 0.71 



0.25 Molar 



0.5 " 



3 " 



4 " 



- I.038 



- 0.73 



- 0.55 



- 0.55 

 + 0.005 

 -f- 0.68 

 + 1-37 



Sodium Sulphate. Ammonium Sulphate. 



0.25 Molar 



0-5 " 



1 " 



2 " 



3 " 



- 1.038 



- 1. 5i 



- 1.65 



- 1-79 



- 1.86 



- 1.89 



0 



o.S " 



1 " 



3 " 



4 " 



— 1.038 



— 1.52 



— 1.72 



— 1.90 



— 2.05 



— 2.14 



— 2.18 



Magnesium Sulphate 



0 



0.25 Molar 



0.5 " 



- 1.038 



- 1.36 



- 1-45 



2 " 



3 " 



- 1-47 



- 1.34 



- 1. 12 



certain that this substance has considerable hydrating power, 

 but this is masked in our results by the large amount of poly- 

 merization which the sulphates undergo." 



The curve of the freezing point depression of magnesium sul- 

 phate plotted against concentration shows a depression to about 

 0.5 molar, from which point the depression decreases for higher 

 concentrations. In this respect there is a slight similarity to its 



