MICROCHEMICAL REACTIONS OF THE COMMON ACIDS 423 



aggregates, globulites br highly refractive grains rhomboidal in 

 outline. 



c. To test the character of the gas given off, place in the distilling 

 apparatus, Fig. 153, page 293, exposing a drop of lead acetate 

 to the vapors. 



CHLORIDES. 



a. With Silver Nitrate. See Silver, page 377. 



b. With Lead Nitrate. See Lead, page 371. 



CHLORATES. 



a. Test the material with Rubidium Chloride and a little Potas- 

 sium Permanganate to be sure perchlorates are absent (see Experi- 

 ment a, Method IX, page 310). Then convert into Perchlorates 

 as follows: 



Dissolve a little of the material in a drop of water at the comer 

 of an object slide, evaporate to dry ness. Add a drop of sul- 

 phuric acid, evaporate to dryness and heat until white fumes 

 escape. Add a second drop of acid and heat until the excess 

 of sulphuric acid has been driven off. Cool. Add a tiny drop 

 of potassium permanganate (just sufficient to color the drop) 

 and a crystal of rubidium chloride. Allow to stand for a short 

 time and examine. Characteristic crystals of rubidium per- 

 chlorate will separate, colored pink or violet through adsorption 

 of the permanganate. 



The chlorate is only partially converted into the perchlorate, 

 hence this test is not always successful, and is of little value in 

 complex mixtures. 



CHROMATES; BICHROMATES. 



a. Test with Silver Nitrate in nitric acid solution. See Silver, 

 page 381 ; Chromium, page 404. 



b. Test with Strontium Acetate. See page 347. 



c. Bichromates give no separation of crystals with Manganous 

 Sulphate; Chromates do. See Manganese, page 407. 



CYANIDES. 



a. Place the material in the glass crucible of apparatus, Fig. 

 153, page 293; moisten with dilute sulphuric acid, cover with 



