

360 METALS AND THEIR COMBINATIONS. 



While the above is the principal reaction, there is formed also some anti- 

 mony oxide. 



Experiment 48. Intimately mix about 0.5 gramme of finely powdered black 

 antimony sulphide with some sodium carbonate and potassium cyanide. 

 Heat this mixture with a blowpipe flame on charcoal till it fuses thoroughly 

 and a bead of metallic antimony is obtained. Drop the molten antimony 

 from the height of about a foot upon a sheet of paper and notice that 

 characteristic grayish-white streaks are formed, radiating in all directions. 

 Test the crust (left on the charcoal) on a silver coin for sulphur. Examine 

 another bead of antimony for cplor, hardness, malleability, etc. ; then try its 

 solubility in acids in the order of hydrochloric, dilute sulphuric, nitric, and 

 nitre-hydrochloric acids. 



Antimony pentasulphide, Sb 2 S 5 (Golden sulphur et of antimony). 

 A red powder, which, like antimonotis sulphide, forms sulpho-salts. 

 It may be obtained by precipitation of acid solutions of antimonic 

 acid by hydrogen sulphide. 



Antimonous chloride, SbCl 3 (Antimony terchloride, Butter of anti- 

 mony). Obtained by boiling the native sulphide with hydrochloric 

 acid: 



Sb 2 S 3 4- 6HC1 = 3H 2 S 4- 2SbCl 3 . 



The clear solution is evaporated and the remaining chloride dis- 

 tilled, when it is obtained as a white, crystalline, semi-transparent 

 mass. 



By passing chlorine over antimonous chloride it is converted into 

 antimonic chloride, SbCl 5 , which is a fuming liquid. 



Experiment 49. Boil about 2 grammes of black antimony with 10 c. c. of 

 hydrochloric acid until most of the sulphide is dissolved. Set aside for sub- 

 sidence, pour off the clear solution of antimonous chloride, evaporate to about 

 half its volume and use solution for next experiment. 



Antimonous oxide (Antimony trioxide). When antimonous chlo- 

 ride is added to water decomposition takes place similar to the one 

 which normal bismuth salts undergo by the action of water, viz., a 

 white precipitate of oxy-chloride of antimony (antimonyl chloride), 

 BbOCl, is formed, which, however, is mixed with antimonous oxide, 

 as the following two reactions take place : 



SbCl 3 + H 2 O = SbOCl 4- 2HC1. 

 2SbCl 3 4- 3H 2 = Sb 2 3 4- 6HC1. 



The relative proportions of the two constituents depend on the 

 mode of manipulating and on the quantity of water used. 



The white precipitate was formerly known as powder of Algaroth. 



