A REARRANGEMENT OF PROCEDURE FOR THE REMOVAL OF PHOS- 

 PHATE IONS FROM THE IRON AND ALKALINE EARTH 



GROUPS. By CARLETON BELL NICKERSON, M. A., 

 Instructor in Chemistry, Dalhousie University, Halifax, 



N. S.* 



Read 8th April, 1912. 



The 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 

 nietals 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 H., S in acid solution) 

 with a few drops of cone. HN0 3 and boil until all H 2 S 

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

 of strong NH 4 C1 solution and a slight excess of NH 4 OH. 

 Filter : 



Notes. 1. The HN O 3 is added to oxidize any iron that mnv 

 be present, which after the H 2 S treatment is always in the ferrous 

 condition. 



2. The treatment with HN O 3 may also cause a slight precipitati?n 

 of culphur from the H 2 S. 



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

 of N H 4 O H, since the precipitate of Al(0 H) 3 is somewhat soluble 

 in an excess. 



Contributions from the Science Laboratories of Dalhousie University [Chemistry.] 



(95) 



