1NSTIM "MI-NTS AND rill-MH "Al, TKSTS 



Ammonium, MI ,. 



Ammonia, NII.-i, is :i u,a> :it ordinary temperatures; when di 

 solved in water it form- ammonium hydroxide. X 1 1 .( )H, commonly 

 called ammonia, li i> driven from the water solution by heat 

 M Nil,, which possesses a very marked odor, reacts as a base in 

 forming salts, which in their chemical behavior are very similar 

 to the salts of potassium, except its salts are volatile, and for that 

 reason ammonium is termed the volatile alkali. 



a. If a compound containing ammonium is boiled in a test tube 

 with sodium hydroxide, ammonia will be liberated and carried off 

 in the steam, when it is detected by the odor; or if a glass rod 

 moistened with HC1 is held over the tube, a white cloud of am- 

 monium chloride, NH 4 C1, will appear. 



GROUP II: THE ALKALI EARTHS 



Barium, strontium, and calcium are precipitated from alkaline 

 solutions as carbonates, phosphates, oxalates, or borates. They 

 are alike also in yielding before the blowpipe flame colorations. 

 Magnesium, generally placed in this group, yields no flame color- 

 ation, and its salts are more soluble. They all agree in that, if 

 their salts, except the silicates, borates, and phosphates, are ignited, 

 they yield an alkaline reaction with turmeric paper. 



Barium, Ba. Atomic weight, 137.37. Fusing point, 850 C. 



a. Flame. If a mineral containing barium, except silicates, is 

 heated at the tip of blue cone in the O. F., it will yield a yellowish 

 green flame. Borates and phosphates also yield green flames that 

 must not be mistaken for barium. Silicates must be tested as in 6. 



6. Wet test. Barium salts in solution yield a white precipitate 

 with sulphuric acid. This precipitate when filtered out and dried 

 will yield a yellowish green flame. 



Silicates and insoluble compounds are fused with four parts of 

 soda, boiled in water and filtered. The residue will contain the 

 barium as barium carbonate. This is dissolved in a few drops of 

 dilute HC1. The solution allowed to run through the filter is col- 

 lected in a test tube. In this solution H 2 SO 4 will precipitate the 

 barium" as before. 



Illustration. Heat a small fragment of witherite, BaCO 3 , in 

 O. F. After continued heating observe the yellowish green flame. 

 Place the ignited fragment on turmeric paper ; moisten with a drop 

 of water. It will react alkaline. Dissolve a little powdered mineral 



