Antimonious and Antimonic Acids

Obtained by acting on metallic antimony, or on the sesqui-chloride, with an excess of chlorine. It is also formed when powdered antimony is introduced into chlorine gas, when it bums with a vivid light. It is a colourless, volatile fuming liquid, which is decomposed by water, yielding hydrochloric and antimonic acids. 

This is the white powder formed when sesquichloride of antimony is thrown into water, as above described, under the head of sesquioxide. It soon changes into crystals, and is a definite 

Bromine and antimony combine readily, and form a volatile crystalline solid. 

This is the common ore of antimony, and is generally a dark grey radiated fusible ciystaHine mass, Sp. G. 4 62. When formed by the action of sulphuretted hydrogen on salts of antimony, it is precipitated as a hydrate, of a brownish orange colour, 

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The free oxy-acids of antimony are even less stable than those of arsenic. Various hydrated forms of the trioxide and pentoxide have been described as antimonious and antimonic acids, but their structures are unknown. Finite oxy-ions SbO ", SbOJ, and Sb207 do not exist. Compounds formerly described as ortho-, meta-, and pyro-antimonates all contain Sb " octahedrally coordinated by oxygen, either as Sb(OH)g ions, in compounds which were once described as hydrated meta- or pyro-antimonates, or as SbOg groups in the compounds of type (b), which are best described as complex oxides, and not as antimonates, for reasons given later. 

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