| Identification | More | [Name]
ARSENIC ACID | [CAS]
7778-39-4 | [Synonyms]
Arsenic acid，hemihydrate
acidearseniqueliquide
acidearseniqueliquide(french)
arsenicacid(h3aso4)
arsenicacid,[solid]
arsenicacid,liquid
arsenicacid,solid
caswellno056
chromatedarsenicals
crabgrasskiller
desiccantl-10
dessicantl-10
epapesticidechemicalcode006801
hi-yielddesiccanth-10
orthoarsenic
orthoarsenicacid
orthoarsenicacidhemihydrate
rcrawastenumberp010
scorch
zotox | [EINECS(EC#)]
231-901-9 | [Molecular Formula]
AsH3O4 | [MDL Number]
MFCD00036290 | [Molecular Weight]
141.94 | [MOL File]
7778-39-4.mol |
| Chemical Properties | Back Directory | [Appearance]
white translucent crystals | [Melting point ]
36.1℃ [CRC10] | [Boiling point ]
160℃[at 101 325 Pa] | [density ]
2–2.5 [HAW93] | [vapor pressure ]
18.45hPa at 25℃ | [solubility ]
very soluble in H2O, ethanol | [form ]
exists only in solution | [pka]
3.09±0.10(Predicted) | [color ]
exists only in solution | [Stability:]
Incompatible with metals. | [Water Solubility ]
very soluble H2O, EtOH [CRC10] | [CAS DataBase Reference]
7778-39-4(CAS DataBase Reference) | [EPA Substance Registry System]
Arsenic acid (7778-39-4) |
| Hazard Information | Back Directory | [Chemical Properties]
Arsenic acid is a clear, white, semi-transparent crystal (sugar or sand-like) material.
Arsenic acid is one of the most commercially important pentavalent compounds of
arsenic. It is used for wood treatment/wood preservative, as a drying agent, a soil sterilant, and to make other arsenates. It is a broad-spectrum biocide, a fi nishing agent
for glass and metal, and a reagent in the retard of dyestuffs and organic arsenic compounds. Arsenic acid decomposes on heating, producing toxic and corrosive fumes. It
is a strong oxidant and reacts with combustible and reducing materials and attacks/
damages metals to produce toxic and flammable arsine. It is soluble in water and forms
the arsenate ion. | [Uses]
Pesticides; herbicides; fungicides; algicides. | [Definition]
Any salt or ester of arsenic acid. They are distributed widely in nature and contaminate coal and metal ores. Arsenates uncouple oxidative phosphorylation by replacing inorganic phosphorous in the ATP. | [General Description]
White crystals. Melting point 95°F. Excessive drying produces As2O5.5/3H2O. | [Hazard]
Carcinogen; toxic. | [Reactivity Profile]
ARSENIC ACID may evolve very toxic gaseous arsine (AsH3) from contact with active metals, such as zinc and aluminum [Inorganic Chemicals Handbook, I, p. 175]. When heated to decomposition, ARSENIC ACID, SOLID(7778-39-4) produces toxic fumes of metallic arsenic [Sax, 9th ed., p. 271]. The solution is weakly acidic and a weak oxidizing agent. Reacts with alkalis to generate some heat and precipitate arsenates. | [Air & Water Reactions]
Hygroscopic. Water soluble. | [Health Hazard]
Arsenic acid is absorbed into the body by inhalation of its vapor, through the skin, and
by ingestion. Arsenic acid is an eye irritant and may cause burns. Most injuries result
from exposure to dusts, causing conjunctivitis, lacrimation, photophobia, and chemosis.
Exposures to arsenic acid cause poisoning with symptoms of irritation of the eyes, the
skin, the respiratory tract, respiratory distress, sore throat, nausea, vomiting, diarrhea,
poor appetite, and stomach cramps. Arsenic acid also causes effects on the blood, cardiovascular system, gastrointestinal tract, liver, and peripheral nervous system, leading to polyneuropathy and convulsions. Repeated exposures to high concentrations of arsenic
acid have been reported to cause nerve damage, with “pins and needles,” numbness, and
weakness of the arms and legs, and even death. Tachycardia is frequently reported following ingestion of arsenic acid salts and is contributed to by anxiety, intravascular fl uid
depletion, and possibly direct arsenic-induced cardiotoxicity.
| [Health Hazard]
Ingestion cuases irritation of stomach, weakness, other gastrointestinal symptoms. Overdose can cause arsenic poisoning, but symptoms are delayed. | [Fire Hazard]
Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes. Some are oxidizers and may ignite combustibles (wood, paper, oil, clothing, etc.). Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated. | [Physical properties]
Hygroscopic translucent crystals; density between 2 to 2.5 g/cm3; melts at 35.5°C; loses water when heated to 160°C; highly soluble in cold water; soluble in alcohol, glycerol and alkalies. | [Preparation]
Arsenic acid is prepared by treating arsenic trioxide with concentrated nitric acid; or by combination of arsenic pentoxide with water. The latter reaction is very slow. It is also formed when meta- or pyroarsenic acid is treated with cold water. |
| Safety Data | Back Directory | [RIDADR ]
1554 | [HazardClass ]
6.1(a) | [PackingGroup ]
II | [storage]
Arsenic acid should be kept stored in an area without drain or sewer access. It should be
separated from strong oxidants, strong bases, metals, strong reducing agents, food, and
feedstuffs. Occupational workers should keep arsenic acid in a cool, well-ventilated area,
away from heat. Workers should avoid storing or transporting arsenic acid with aluminium, copper, iron, or zinc. | [Precautions]
Occupational workers should be extremely careful and cautious during handling and use
of arsenic acid. | [Safety Profile]
Confirmed human
carcinogen. Poison by ingestion. An
experimental teratogen. Human mutation
data reported. When heated to decomposition it emits toxic fumes of
arsenic. See also ARSENIC
COMPOUNDS. | [Hazardous Substances Data]
7778-39-4(Hazardous Substances Data) |
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