0.1 MinTHF , 15489-27-7
Synonym(s):
Selenious acid
CAS NO.：15489-27-7
Empirical Formula: H2O3Se
Molecular Weight: 128.97
MDL number: MFCD00134090
EINECS: 231-974-7
PRODUCT Properties
| Melting point: | 70 °C (dec.) (lit.) |
| Boiling point: | 684.9 °C(lit.) |
| Density | 3.004 g/mL at 25 °C (lit.) |
| vapor pressure | 2.7hPa at 15℃ |
| Flash point: | 690°C |
| storage temp. | Store at RT. |
| solubility | H2O: soluble |
| form | powder |
| pka | 2.46(at 25℃) |
| color | White to almost white or light pink |
| Specific Gravity | 3.004 |
| PH | 3.15(1 mM solution);2.47(10 mM solution);1.9(100 mM solution) |
| Water Solubility | 167 g/100 mL (20 ºC) |
| Sensitive | Hygroscopic |
| Merck | 14,8430 |
| Exposure limits | ACGIH: TWA 0.2 mg/m3 NIOSH: IDLH 1 mg/m3; TWA 0.2 mg/m3 |
| Stability: | Stable. |
| CAS DataBase Reference | 7783-00-8(CAS DataBase Reference) |
| EPA Substance Registry System | Selenious acid (H2SeO3) (7783-00-8) |
Description and Uses
Selenious acid is a colourless, deliquescent crystal in appearance. It decomposes on heating,
producing water and toxic fumes of selenium oxides.
It is incompatible with strong reducing agents, organic materials, and finely powdered
metals and reacts on contact with acids producing toxic gaseous hydrogen selenide.
Selenious acid is a non-combustible chemical. On fire/burning, it emits irritating or toxic
fumes (or gases).
The major use of selenious acid is in changing the colour of steel, especially the steel in
guns from silver grey to blue grey. It is also used for the chemical darkening and patination
of copper brass and bronze, producing a rich dark-brown colour that can be further
enhanced with mechanical abrasion.
As an oxidizing agent, as a reagent for alkaloidsSelenous acid is used in steel guns, wherein it changes the color of the steel from silver-grey to blue-grey. It serves as an important component of the Mecke reagent, which is utilized for drug testing. It acts as a source of selenium. It acts as a reagent for alkaloids and an oxidizing agent. Further, it is used in labeling radiopharmaceuticals. It is involved in the organic synthesis for the preparation of glyoxal.
Safety
| Symbol(GHS) |    GHS06,GHS08,GHS09 |
| Signal word | Danger |
| Hazard statements | H301+H331-H373-H410 |
| Precautionary statements | P273-P301+P310+P330-P304+P340+P311-P314 |
| Hazard Codes | T,N,Xi |
| Risk Statements | 36/38-50/53-33-23/25-52/53 |
| Safety Statements | 61-60-45-28A-20/21-26-28 |
| RIDADR | UN 3440 6.1/PG 3 |
| WGK Germany | 3 |
| RTECS | VS7700000 |
| F | 3 |
| TSCA | Yes |
| HazardClass | 8 |
| PackingGroup | III |
| HS Code | 28111980 |
| Hazardous Substances Data | 7783-00-8(Hazardous Substances Data) |
