INSTIMMKXTS AM) C'HK.MH '.\I. TESTS 



this solution will neutrali/.e 1 re. of the dilute acid-. It i- u-ed to 

 precipitate h\dn>\ides. 



Sodium phosphate, disodiuin phosphate, Na.JI l'< ), . 1'J II < >. 

 Pi-solve 171 gin. in water and dilute to u liter. This solution is 

 u-ed in the te>( for magnesium. 



Ammonia, ammonium hydroxide, NH 4 ()H. Strong ammonia 

 is spr. .90, it contains i_ )( .) per cent. NH 3 . One part of the strong 

 solution diluted with 3 parts of water will yield a solution nearly 

 ">n. 1 cc. of this solution will neutralize 1 cc. of the dilute acids. 

 Ammonia is used in many wet tests and to precipitate hydroxides. 



Ammonium sulphide, (NH 4 ) 2 S, made by saturating the dilute 

 ammonium solution with H 2 S. It is used to precipitate metallic 

 sulphides and in some cases hydroxides. 



Ammonium carbonate, (NH 4 ) 2 COs. To make a 5n. solution, 

 dissolve 200 gms. of commercial ammonium carbonate in 350 cc. 

 of the dilute ammonia, and dilute to a liter. It is used to precipi- 

 tate metallic carbonates. 



Ammonium oxalate, (NH4) 2 C 2 O 4 . 2 H 2 0. To make a normal 

 solution dissolve 80 gm. in water and dilute to one liter. Used in 

 to ting for calcium. 



Ammonium molybdate, (NH 4 ) 2 Mo0 4 . Dissolve 60 gm. of 

 molybdic trioxide, MoO 3 , in 440 cc. of water and 60 cc. of strong 

 ammonia. This solution is slowly poured with constant stirring into 

 250 cc. concentrated nitric acid previously diluted with 250 cc. of 

 water. Let the solution stand for 24 hours, when it is either 

 filtered or decanted. On further standing the molybdic acid 

 gradually separates, forming a light yellow crust on the sides and 

 bottom of the bottle, thus losing its strength on standing. This 

 reagent is used to precipitate phosphoric acid. 



Barium hydroxide, Ba(OH) 2 . 8 H 2 O. A n. solution is used; 

 dissolve 31 gm. in one liter of water. Used in the detection of 

 carbon dioxide. 



Barium chloride, BaCl 2 . 2 H 2 O. To make a normal solution 

 dissolve 122 gm. in a liter of water. The solution is used in the 

 tests for sulphates. 



Lead acetate, Pb(CH 3 COO) 2 . 3 H 2 O. To make a normal 

 solution dissolve 189 gm. in a liter of water. It is used in the 

 detection of chromates. 



Silver nitrate, AgNOs. To make normal solution 34 gm. 

 in a liter of water. It is used in the test for chlorine. 



Ferrous sulphate, FeSO 4 . 7 H 2 O. To make a normal solu- 

 2o 



