Sodium arsenite
Chemical compound
From Wikipedia, the free encyclopedia
Sodium arsenite usually refers to the inorganic compound with the formula NaAsO2. Also called sodium meta-arsenite, it is an inorganic polymer consisting of the infinite chains [AsO2]n−
n associated with sodium cations, Na+. The polymer backbone has the connectivity -O-As(O−)-.[2] backbone. Sodium ortho-arsenite is Na3AsO3.[3] Both compounds are colourless solids. A mixture of sodium meta-arsenite and sodium ortho-arsenite is produced by treating arsenic trioxide with sodium carbonate or sodium hydroxide.[4] Sodium arsenite is amorphous, typically being obtained as a powder or as a glassy mass.
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| Names | |
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| IUPAC name
sodium arsenite | |
| Other names
sodium arsenate(III) | |
| Identifiers | |
3D model (JSmol) |
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| ChEBI | |
| ChEMBL | |
| ChemSpider | |
| DrugBank | |
| ECHA InfoCard | 100.029.154 |
| EC Number |
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| KEGG | |
PubChem CID |
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| RTECS number |
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| UNII | |
| UN number | 1686 2027 |
CompTox Dashboard (EPA) |
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| Properties | |
| NaAsO2 | |
| Molar mass | 129.91 g/mol |
| Appearance | white or grayish powder hygroscopic |
| Density | 1.87 g/cm 3 |
| Melting point | 550 °C (1,022 °F; 823 K) decomposes |
| 156 g/100 mL | |
| Solubility | slightly soluble in alcohol |
| Hazards | |
| GHS labelling: | |
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| Danger | |
| H300, H301, H310, H331, H350, H410 | |
| P201, P202, P261, P262, P264, P270, P271, P273, P280, P281, P301+P310, P302+P350, P302+P352, P304+P340, P308+P313, P310, P311, P312, P321, P322, P330, P361, P363, P391, P403+P233, P405, P501 | |
| NFPA 704 (fire diamond) | |
| Lethal dose or concentration (LD, LC): | |
LD50 (median dose) |
41 mg/kg (rat, oral) |
| NIOSH (US health exposure limits): | |
PEL (Permissible) |
[1910.1018] TWA 0.010 mg/m3[1] |
REL (Recommended) |
Ca C 0.002 mg/m3 [15-minute][1] |
IDLH (Immediate danger) |
Ca [5 mg/m3 (as As)][1] |
| Safety data sheet (SDS) | External MSDS |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Health effects
Sodium arsenite can be inhaled or absorbed through the skin. Along with its known carcinogenic and teratogenic effects, contact with the substance can yield symptoms such as skin irritation, burns, itching, thickened skin, rash, loss of pigment, poor appetite, a metallic or garlic taste, stomach pain, nausea, vomiting, diarrhea, convulsions, decreased blood pressure, and headache. Severe acute poisoning may lead to nervous system damage resulting in weakness, poor coordination, or “pins and needles” sensations, eventual paralysis, and death.[5][6]
Application
Sodium arsenites are primarily used as a pesticide, but has other uses such as hide preservative, antiseptic, dyeing, and soaps.[7]
Sodium arsenite is an appropriate chemical stressor to induce the production of heat shock proteins,[8] and the formation of cytoplasmic stress granules.[9]
Sodium arsenite can be used as a reducing agent in organic chemistry, as it is able to reduce a trihaloalkane to a dihaloalkane:[citation needed]
- CHBr3 + Na3AsO3 + NaOH → CH2Br2 + Na3AsO4 + NaBr