[ ARCHIBALD-KERN] SOLUBILITIES OF THE CHLOROPLATINATE 



15 



The Solubility of the Chloroplatinate and Chloriridate of Ammonia 

 in Ammonium Chloride Solutions. 



As the completeness of the separation of the metals under in- 

 vestigation depends to a considerable extent upon the solubility 

 of the respective salts in solutions of the precipitating agents, measure- 

 ments were made of the solubility of the chloroplatinate and chlori- 

 ridate in ammonium chloride solutions. The solutions were prepared 

 from the recrystallized ammonium chloride that had been dried at 

 100°. The exact amount of salt necessary to yield a definite volume 

 of a twice normal solution was weighed out, dissolved and diluted 

 to the required volume. Normal, fifth normal and tenth normal 

 solutions were then prepared, by measuring out exact portions of this 

 solution with standardized pipettes and diluting to definite volumes. 

 The results obtained are shown below in Table V. The values repre- 

 sent the number of grams of substance dissolved in 100 gramms of 

 the solvent. The concentration of the ammonium chloride is expressed 

 in equivalent gram molecules per liter. The temperature was 20°. 



Solubility of Ammonium Bromoplatinate in Ammonium Bromide 



Solutions. 



For the sake of comparison the following measurements were 

 made of the solubUity of the bromoplatinate in ammonium bromide 

 solutions. The solutions were prepared in the same manner and the 

 values refer to the same units as in the case of the chloride solutions. 



It will be noted that, as we would expect, the solubility in all 

 three cases decreases very rapidly as the concentration of the ammon- 



