370 Gooch and McClenahan — Typical Hydrous Chlorides. 



washed with concentrated hydrochloric acid, sucked as dry as 

 possible by the pump, and exposed seventy -two hours in a desic- 

 cator containing quicklime, to absorb free hydrogen chloride, 

 as well as sulphuric acid to take up water. The composition 

 of the product was fixed by determining the aluminum as the 

 oxide by ignition with mercuric oxide,* and the chlorine by 

 precipitation with silver nitrate, as shown in the following 

 analyses : 



Analysis I. 



Aluminum 11*17 



Chlorine 43*92 



Water (by difference).. 44*91 



100*00 



Analysis II. 



Theory for 

 AlCV6H a O. 



11*21 



11*20 



44*18 



44*05 



44*61 



44*75 



100*00 



100*00 





<i W J* 80' ?«' '••* /'«" /*■•* /3 o* *»o* /*»" lit' ij? /tt' /fo' »••* ■*■'»' *" 



Weighed portions of this preparation lost practically nothing 

 in three weeks at the ordinary temperature over sulphuric acid, 

 calcium chloride, and phosphorous pentoxide, and remained 

 almost unchanged when heated to 98°. 



The details of two parallel series of experiments in which 

 portions of the hydrous aluminum chloride were heated in air 

 or in a current of hydrogen chloride are recorded in Table III, 

 and the course of the change in weight and loss of chlorine at 

 various temperatures in air and in hydrogen chloride are shown 

 in the diagram. 



From the results of these experiments it appears that the 

 inhibitive action of the atmosphere of hydrogen chloride upon 

 the dehydration of hydrous aluminum chloride is marked at the 

 lower temperatures. While the hydrous salt when heated in 



* Gooch and Havens : This Jour, vi, 45 (1898). 



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