Special tests for small amounts of antimony

When the stibine-hydrogen mixture is passed into a solution of silver nitrate (Hofmann s test) a black precipitate of silver antimonide Ag3Sb is obtained this is decomposed by the excess of silver nitrate into silver and antimony(III) oxide  

It is best to dissolve the precipitate in a solution of tartaric acid and to test for antimony with hydrogen sulphide in the usual manner. 

18 TIN, Sn (Ar 118-69) - Tin(II) Tin is a silver-white metal which is malleable and ductile at ordinary temperatures, but at low temperatures it becomes brittle due to transformation into a different allotropic modification. It melts at 231-8°C. The metal dissolves slowly in dilute hydrochloric and sulphuric acid with the formation of tin(II) (stannous) salts  

Dilute nitric acid dissolves tin slowly without the evolution of any gas, tin(II) and ammonium ions being formed  

With concentrated nitric acid a vigorous reaction occurs, a white solid, usually formulated as hydrated tin(IV) oxide Sn02. xH20 and sometimes known as metastannic acid, being produced  

Marsh s test this test is carried out exactly as described for arsenic. The stibine, SbH3 (mixed with hydrogen), which is evolved, burns with a faintly bluish-green flame and produces a dull black spot upon a cold porcelain dish held in the flame this deposit is insoluble in sodium hypochlorite or bleaching powder solution, but is dissolved by a solution of tartaric acid (difference from arsenic). 

Gutzeit s test a brown stain is produced which is soluble in 80% alcohol, provided the concentration of antimony is not too high. 

Fleitmann s test negative results are obtained when this is applied to antimony compounds (distinction from arsenic). 

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