533 



Chemistry. — "The system: copper sulphate, copper chlorid, potas- 

 sium sulphate, potassium chlorid and water at2>i)°'\ By Prof. 

 F. h. H. ScHREiNEMAKERs and Miss W. C. DE Baat. 



1. Introduction. 



In previous communications ^) we have discussed tlie quaternary 

 systems: 



Cu SO, — Cu CI, — (NHJ, SO, — NH, CI — water 

 and Cu SO, — Cu CI, — Na, SO, — Na CI - water 



Now we shall discuss the system 



Cu SO, — Cu CI, — K, SO, — KCl — water, 

 which we have examined at 30°. 



As solid substances occur at 30°: 



the anhydric salts : K,SO, and KCl, 



the hydrates: CuSO, . 5H,0 and CuCl, . 2H,0, 



the doublesalts: CuSO, . K,SO, . 6H,0 and CuCl, . 2KC1 . 2H,0. 



Further a peculiar salt exists with the composition : 



Cu SO,. K, CI, or K, SO,. Cu CI, 

 with or without one molecule H,0, while sometimes as metastable 

 solid phase a salt with the composition : 



2CuS0, . 3K,C1, . H,0 

 has occurred. 



In fig. 1 the equilibria occurring at 30° are i-epresented schematic- 



^jj'^t 



1) These Communications 17, 586, (1909), 19 1222 (1911) and Zeitschr. fur Phys. 

 Chemie 69, 557, (1909;. 



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