Arsenic (III) chloride

Structural formula
General
Surname	Arsenic (III) chloride
other names	Arsenic trichloride Arsenic butter
Molecular formula	AsCl 3
Brief description	colorless, oily liquid that smokes in air
External identifiers / databases
CAS number 7784-34-1 EC number 232-059-5 ECHA InfoCard 100.029.144 PubChem 24570 ChemSpider 22974 Wikidata Q411245
properties
Molar mass	181.28 g mol −1
Physical state	liquid
density	2.16 g cm −3
Melting point	−16 ° C
boiling point	130.2 ° C
Vapor pressure	13 h Pa (20 ° C)
solubility	exothermic reaction with water
Dipole moment	1.59 (8) D (5.3 x 10 -30  C  ·  m )
Refractive index	1.604 (16 ° C)
safety instructions
GHS hazard labeling from  Regulation (EC) No. 1272/2008 (CLP) , expanded if necessary danger H and P phrases H: 301-331-410 P: 261-273-301 + 310-311-501
MAK	not established as a carcinogen
Toxicological data	48 mg kg −3 ( LD 50 ,  rat ,  oral ) 80 mg kg −3 ( LD 50 ,  rat ,  transdermal )
Thermodynamic properties
ΔH f 0	−305.0 kJ / mol
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C

Arsenic trichloride is a chemical compound of the elements arsenic and chlorine with the empirical formula AsCl ₃ . It is a colorless, oily liquid that smokes in air .

Extraction and presentation

Arsenic trichloride can be obtained by burning arsenic in chlorine gas :

${\displaystyle \mathrm {2\ As(s)+3\ Cl_{2}(g)\rightarrow 2\ AsCl_{3}(g)} }$

Arsenic burns in chlorine gas to form arsenic trichloride.

Arsenic (III) oxide can also be used as the starting material , through which anhydrous hydrogen chloride is passed at 180–200  ° C :

${\displaystyle \mathrm {As_{2}O_{3}(s)+6\ HCl(g)\rightarrow 3\ H_{2}O(g)+2\ AsCl_{3}(g)} }$

Arsenic trioxide reacts with hydrogen chloride to form water and arsenic trichloride.

Another possibility is the production from arsenic trioxide, sulfur dichloride and chlorine.

properties

Arsenic trichloride decomposes when heated and under the influence of light. Humidity causes it to form corrosive vapors of hydrogen chloride and toxic arsenic (III) oxide . It reacts violently with strong oxidizing agents , water and bases .

use

Arsenic trichloride is used for pickling and burnishing of metals .

safety instructions

Arsenic (III) chloride must not be brought into contact with water or oxidizing agents. Contact with water leads to decomposition with formation of corrosive hydrogen chloride .

Acute symptoms of poisoning are expressed by irritating and corrosive effects on the eyes, respiratory tract and skin, sometimes with permanent damage. It can be assumed that toxic amounts of arsenic can enter the body through absorption through the skin.

As an antidote to arsenic, dimercaprol or dimercaptopropane sulfonic acid come into question, the latter being preferred because of their greater effectiveness and, at the same time, fewer side effects.

Individual evidence

1. ↑ Entry on arsenic trichloride. In: Römpp Online . Georg Thieme Verlag, accessed on July 15, 2014.
2. ↑ ^{a b c d e f} data sheet arsenic (III) chloride from AlfaAesar, accessed on February 3, 2010 ( PDF )(JavaScript required) .
3. ↑ David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Dipole Moments, pp. 9-51.
4. ↑ David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Index of Refraction of Inorganic Liquids, pp. 4-140.
5. ↑ ^{a b c} Entry on arsenic (III) chloride in the GESTIS substance database of the IFA , accessed on January 13, 2017(JavaScript required) .
6. ↑ Not explicitly listed in Regulation (EC) No. 1272/2008 (CLP) , but with the specified labeling it falls under the group entry arsenic compounds, with the exception of those named in this appendix in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA) on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .
7. ↑ ^{a b} Gigiena Truda i Professional'nye Zabolevaniya. Labor Hygiene and Occupational Diseases. Vol. 27 (4), p. 54, 1983.
8. ↑ ^{a b} Entry on arsenic (III) chloride in the ChemIDplus database of the United States National Library of Medicine (NLM) .
9. ↑ David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Standard Thermodynamic Properties of Chemical Substances, pp. 5-5.
10. ↑ G. Brauer (Ed.), Handbook of Preparative Inorganic Chemistry 2nd ed., Vol. 1, Academic Press 1963, p. 596.