Antimony trioxide
- Antimony trioxide
- Antimony trioxide
- Antimony white
- Antimony bloom
- Antimonigsäureanhydrid
- Senarmontite
- Valentinite
- White antimony
White, odorless solid
Fixed
- 5.7 g · cm -3
- 5.19 g · cm -3 ( cubic form )
655 ° C
1425 ° C
Insoluble in water
Attention
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Antimony ( III) oxide (also referred to as antimony trioxide ) is an antimony compound having the empirical formula Sb2O3. It belongs to the class of oxides.
Occurrence
Antimony ( III) oxide is used as a natural compound in the form of senarmontite minerals and valentinite before.
Production and representation
Antimony trioxide is technically by heating antimony trisulfide ( gray antimony, stibnite ) in air ( roasting ) or obtained by burning antimony.
In the hydrolysis of antimony ( III) chloride at room temperature, the metastable valentinite that gradually merges into senarmontite when treated with alkalis formed.
Properties
Physical Properties
Antimony ( III) oxide shows thermochromic properties. When heated to temperatures significantly above 600 ° C, the compound becomes yellow. Reversible, the connection is again on cooling white. Cause of the color change is a polymorphic, enantiotropic transformation of the white cubic crystal form ( senarmontite ) to a yellow rhombic crystal form ( valentinite ) at 606 ° C. The enthalpy of formation of the cubic form is ΔfH = -720.5 kJ · mol - 1, the rhombic form ΔfH = -708.5 kJ · mol -1, so that for the polymorphic transformation a transition enthalpy of 12 kJ · mol? TH = -1 results.
Chemical Properties
Antimony trioxide is a white crystalline powder that is insoluble in water but dissolves in concentrated acids and alkalis. It corresponds in structure to the phosphorus trioxide. By heating it at about 800 ° C, it will take more oxygen to less binding of antimony tetroxide. This is a mixed oxide of Antimontri and antimony pentaoxide dar. As the solubility in concentrated acids - which arise depending on the concentration of acid or neutral salts Oxidsalze - and in alkaline solutions - being formed Antimonite - shows it is an amphoteric oxide with antimony trioxide to.
Use
Antimony trioxide is used mainly as a pigment and in the enamel production. In electroplating, it is used to Antimonieren other metals. It is also used as a catalyst for the production of PET. Along with a doping of tin as ATO ( Antimony Tin Oxide) for transparent conductive coatings of glasses, for example, for display technology and pigments for bright and transparent anti-static coatings. In flame retardants such as decabromodiphenyl ether antimony trioxide is used as a synergist.
Safety
The International Agency for Research on Cancer ( IARC) classifies antimony trioxide as a potentially carcinogenic substance.