801. Arsenic Trichloride

Nomenclature

CAS number: 7784-34-1
Arsenous trichloride; butter of arsenic; fuming liquid arsenic.
AsCl3; mol wt 181.28.
As 41.33%, Cl 58.67%.

Description and references

Prepn: Smith, Ind. Eng. Chem. 11, 109 (1919); Reisener in Ullmanns Encyklopdie der technischen Chemie vol. 3, (Urban & Schwarzenberg, Munich, 1953) p 850; Schenk in Handbook of Preparative Inorganic Chemistry vol. 1, G. Brauer, Ed. (Academic Press, New York, 2nd ed., 1963) p 596.

Properties

Oily liquid. Poisonous. Fumes in air. d425 2.1497. mp 16°. bp 130.21°; bp11 25°. Dipole moment: 2.17. Heat of vaporization 8.9 kcal/mol. Specific heat: 3.19 cal/mol/°C. nD20 1.6006. Dec by water to form As(OH)3 and HCl. One mol AsCl3 can be dissolved in 9 mols H2O, this soln (d 1.53) may be diluted again with another 9 mols H2O giving a soln with d 1.346. Further dilution results in the precipitation of As2O3. Also dec by ultraviolet light. Miscible with, or solvent for, chloroform, carbon tetrachloride, ether, iodine, phosphorus, sulfur, alkali iodides, oils and fats.

Use

In the ceramic industry; in syntheses of chlorine-contg arsenicals, e.g., chloro derivs of arsine.