Atomistry » Arsenic » Chemical Properties » Tetrarsenic Trisulphide
Atomistry »
  Arsenic »
    Chemical Properties »
      Tetrarsenic Trisulphide »

Tetrarsenic Trisulphide, As4S3

Tetrarsenic Trisulphide (Arsenic Tritetritasulphide), As4S3, is obtained by fusing together realgar and an excess of arsenic; after cooling, the product is crushed and extracted with carbon disulphide, or allowed to sublime in a vacuum. Yellow orthorhombic prisms are obtained. This sulphide is also formed in small quantity during the photochemical disintegration of realgar.

The crystals have density 3.60 at 19° C. According to Krenner, the sublimed crystals have axial ratios a:b:c = 0.58787:1:0.88258; the optic axial angle 2Hα = 108°46' and the optical character is positive. The density of this product he gives as 2.60 at 19° C., a much lower value than that above. On warming, the crystals darken to an orange colour. The vapour dissociates at high temperatures, as is shown by the following values of the vapour density: at 792° C., 8.204; at about 1000° C., 6.59; (As4S3 = 13.67).

Minute orange-yellow crystals, of density 3.58, corresponding in composition with As4S3, were obtained from a fumarole in Italy by Schacci and named by him dimorfina, which later became dimorphin or dimorphite. It was described as occurring in two crystalline forms, α- and β-dimorphite, both rhombic, but the α-form is probably identical with orpiment (Dana). The nature of the β-form has not been elucidated and it may be a definite species.

Last articles

Xe in 6AYK
Xe in 6QII
Xe in 6ASM
Xe in 5NSW
Xe in 6FY9
Xe in 5O1K
Xe in 5O27
Xe in 5M69
Xe in 5KPU
Xe in 5I63
© Copyright 2008-2020 by atomistry.com
Home   |    Site Map   |    Copyright   |    Contact us   |    Privacy