A EeARRANGEMENT of i'ROCEDURE FOR THE EeMOVAL OF PHOS- 

 PHATE lOXS FROM THE IrON AND ALKALINE EaRTH 



Groups. — By Carletox Bell Xickersox, M. A., 

 Instructor in Chemistry, Dalhousie University, Halifax, 

 N. S.* 



Read 8th April, 1912. 



Tlie following procedure is the result of several attempts to 

 simplify the various methods in common use for the removal 

 of phosphate ions during the qualitative separation of the 

 metals of the iron and alkaline earth groups. It has been the 

 author's experience that, for the usual college class in qualita- 

 tive analysis, the methods commonly used require rather too 

 much nicety in manipulation to be altogether practicable. The 

 procedure given below has been used by the class in qualitative 

 analysis at Dalhousie University this year with very favorable 

 results. 



1. Procedure. — Treat the solution (after the removal 

 of all the metals precipitated by Hv S in acid solution) 

 with a few drops of cone. HXO., and boil until all HoS 

 is expelled ; filter if necessary. Add at once about % volume 

 of strong XH^Cl solution and a slight excess of NH^OH. 

 Uilter : 



Notes. — 1. The HXO, is added to oxidize any iron that may 

 be present, which after the H, S treatment is always in the ferrouS 

 ■condition. 



2. The treatment with HXO, may also cause a slight precipitat;?n 

 of sulphur from the H., S. 



3. Care must be taken to avoid adding more than a slight excess 

 of X H^ O H, since the precipitate of A1(0 H)^ is somewhat soluble 

 in an excess. 



*C'ontribniions from the Science Laboratories of Dalhousie L'niversity [Chemistry.] 



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