98 REMOVAL OF PHOSPHATE IONS, ETC. 



H CI solution : Add an excess of Na H. Filter and fuse the 

 precipitate with jSFaoCOg on platinum foil. Green color indi- 

 cates Mn. To filtrate add HjS. White precipitate is Zn S. 



Notes. — 1. An excess of NaOH forms a soluble compound with the 

 Zn, Na^ Zn O^, Avhich passes into the filtrate. The Mn is at the same 

 time precipitated as Mn (OH), and converted by fusion with Na., C Og, 

 to the compound Na^ Mn O^, which is green in color. 



9. Procedure. — The filtrate from 7 now contains only 

 the ions of the alkaline earth and alkali groups. These are 

 separated and identified in the usual manner. 



