Antimony

Antimony, Sb, is a metallic main group element, found in Group Vb of the periodic table.

Atomic Number : 51
Relative Atomic Mass : 121.75

Antimony and many of its compounds are highly toxic.

Discovery

Antimony was known in biblical times when its Stibnite ore, Sb2S3, was used as a cosmetic for blackening the eyebrows.

Occurrence

Antimony is found as Stibnite, Sb2S3.
Antimony is also found in Cuprous Thioantimonite, Cu3SbS3,
and Silver Thioantimonite, Ag3SbS3, which are ores used as a source of Copper, Cu, and Silver, Ag.

Preparation

Antimony is prepared in the laboratory by reducing Arsenious Oxide, As4O6, with Carbon.
&t; As4O6 + 3 C ==> As4 + 3 CO2

Manufacture

Antimony is manufactured by heating Stibnite, As2S3 with Scrap Iron, Fe.
&t; As2S3 + Fe ==> 3 FeS + 2 Sb

Properties

Antimony in its elemental form exhibits allotropy and three forms are known.

Crystalline Antimony which is also known as beta-Antimony and Rhombohedral Antimony is the ordinary form which is referred to as Antimony. It is a silver-white solid with a high metallic luster and a crystalline structure. It is brittle and a poor conductor of heat and electricity. Antimony Black is the highly divided powdered form of the metal which is used to coat brass and lead alloys.
alpha-Antimony, Sb, which is also known as yellow Antimony, is formed when Antimony Hydride, SbH3, is treated with air at -90 degC. The properties of this form of Antimony, Sb, may depend on the presence of the hydrides an impurity in the metal.
Explosive Antimony, Sb, is formed on the cathode as a powder which explodes when rubbed or scratched when a current of electricity is passed through a solution of Antimony Trichloride, SbCl3. The peculiar properties of this form of Antimony, Sb, may depend on the presence of the trichloride as an impurity in the metal powder.

Uses

Antimony has many industrial uses and is used

in the manufacture of antimony compounds,
in the form of Antimony Black as a bronzing coating for metals and plaster casts,
in alloys which expand on solidification,
in solders,
in medicines as Tartar Emetic, (i.e. Hydrated Potassium Antimonyl Antimonate),
in the manufacture of enamels,
in the electronics industry in the manufacture of semiconductors, and
in the manufacture of colouring in pottery and ceramics.

Reactions

Antimony, Sb, is similar in to Arsenic in its chemical properties.

Detection and Analysis

Antimony is detected by the orange coloured precipitate that is formed when Hydrogen Sulphide, H2S, is passed into an acidified solution of the substance under test.

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