| Arsine |
| Image:Arsine.png |
| General |
| Systematic name |
Arsane |
| Other names |
Arsenic trihydride |
| Molecular formula |
AsH3 |
| Molar mass |
77.95 g/mol |
| Appearance |
colourless gas |
| CAS number |
[7784-42-1] |
| Properties |
| Density and phase |
4.93 g/l, gas |
| Solubility in water |
0.07 g/100 ml (25 °C) |
| Solubility in organic solvents |
soluble |
| Melting point |
-117 °C (157 K) |
| Boiling point |
-62.5 °C (210 K) |
| Basicity (pKb) |
? |
| Structure |
| Molecular shape |
trigonal pyramidal |
| Dipole moment |
0.20 D |
| Thermodynamic data |
Standard enthalpy
of formation ΔfHogas |
+171.5 kJ/mol |
Standard molar entropy
Sogas |
? J.K−1.mol−1 |
| Hazards |
| MSDS |
External MSDS |
| EU classification |
Very flammable
Highly toxic
Dangerous for
the environment |
| NFPA 704 |
   |
| R-phrases |
R12, R26, R48/20
R50/53 |
| S-phrases |
S1/2, S9, S16,
S28, S33, S36/37,
S45, S60, S61 |
| Flash point |
flammable gas |
| Autoignition temperature |
? °C |
| Explosive limits |
4.5–78 |
| Supplementary data page |
Structure and
properties |
n, εr, etc. |
Thermodynamic
data |
Phase behaviour
Solid, liquid, gas |
| Spectral data |
UV, IR, NMR, MS |
| Related compounds |
| Related hydrides |
Ammonia
Phosphine
Stibine |
Except where noted otherwise, data are given for
materials in their standard state (at 25 °C, 100 kPa)
|
Arsine (AsH3) is a flammable and highly toxic gaseous chemical compound of arsenic and hydrogen. Synonyms include arseniuretted hydrogen, arsenous hydride, arsenic trihydride, and hydrogen arsenide. Some organic compounds based on arsine, such as lewisite, adamsite, Clark I and Clark II, have been developed for chemical warfare.
Arsine is also used in the semiconductor industry for depositing arsenic.
Arsine was formed temporarily, and then decomposed, in the old (but extremely sensitive) Marsh test for the presence of arsenic.
Toxicology
- For the toxicology of other arsenic compounds, see Arsenic, Arsenic trioxide and Arsenicosis.
The toxicity of arsine is distinct from that of other arsenic compounds. The main route of exposure is by inhalation, although poisoning after skin contact has also been described. Arsine binds to the haemaglobin of red blood cells, causing them to be destroyed by the body.
The first signs of exposure, which can take several hours to become apparent, are headches, vertigo and nausea, followed by the syptoms of haemolytic anaemia (high levels of unconjugated bilirubin), haemaglobinuria and nephropathy. In severe cases, the damage to the kidneys can be long-lasting.
Exposure to arsine concentrations of 250 ppm is rapidly fatal: concentrations of 25–30 ppm are fatal for 30 min exposure, and concentrations of 10 ppm can be fatal at longer exposure times. Symptoms of poisoning appear after exposure to concentrations of 0.5 ppm. There is little information on the chronic toxicity of arsine, although it is reasonable to assume that, in common with other arsenic compounds, a long-term exposure could lead to arsenicosis.
See also
Bibliography
Institut national de recherche et de sécurité (INRS), Fiche toxicologique nº 53 : Trihydrure d'arsenic, 2000.
External links
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