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用途
ガラス
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化学的特性
Arsenic pentoxide is an important commercial compound of arsenic. It is a white, shapeless (amorphous), crystalline, lumpy solid or, hygroscopic powder, and is not combustible. It emits irritating or toxic fumes (or gases) in a fi re. Arsenic pentoxide is used as a solid or as a solution in the manufacture of arsenates, weed killer, metal adhesives,
insecticides, fungicide wood preservatives, and colored gases, and in printing and dyeing. It can be synthesized either by burning elemental arsenic in oxygen, or by oxidizing
arsenic trioxide with oxidizing agents, such as ozone, hydrogen peroxide, and nitric acid.
Arsenic pentoxide decomposes to oxygen and As2O3 on heating, and dissolves readily
in water to form arsenic acid, H3AsO4. Arsenic pentoxide reacts violently with bromine
pentafl uoride and reducing agents, and attacks many metals in the presence of water or
moisture.
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物理的性質
White amorphous solid; deliquescent; density 4.32 g/cm3; melts at 315°C; dissolves slowly in water but is very soluble (230 g/100g at 20°C); also soluble in alcohol.
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天然物の起源
Arsenic pentoxide is used to make colored glass; in fungicide formulations; in adhesive for metals; in wood preservatives; in dyeing and printing; and to prepare arsenates.
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使用
Arsenic pentoxide (As2O5) is manufactured by adding oxygen to the trioxide form and is
used to form many arsenic compounds.
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製造方法
Arsenic pentoxide is prepared by dehydration of crystalline arsenic acid at 200°C or above. The former is made by treating arsenic metal or arsenious oxide with nitric acid. Also, the pentoxide can be prepared by the reaction of arsenic trioxide with oxygen under pressure.
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一般的な説明
A white crystalline solid. Noncombustible. Corrosive to metals in the presence of moisture. Toxic by ingestion.
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空気と水の反応
Dissolves in water to give solutions of arsenic acid.
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危険性
Confirmed carcinogen.
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健康ハザード
ARSENIC PENTOXIDE is extremely toxic; the probable oral lethal dose for humans is 5-50 mg/kg, or between 7 drops and 1 teaspoonful for a 150-lb. person. It is irritating to eyes, nose, and throat. Chronic exposure may cause nerve damage to the extremities, alter cellular composition of the blood, and cause structural changes in blood components. There is sufficient evidence that inorganic arsenic compounds are skin and lung carcinogens in humans.
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火災危険
Fire may produce irritating or poisonous gases. Reacts with metal and may give off toxic arsine gas. Hazardous polymerization may not occur.
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安全性プロファイル
Confirmed human
carcinogen. Poison by ingestion and
intravenous routes. Experimental
reproductive effects. Mutation data
reported. Reacts vigorously with Rb2C2.
When heated to decomposition it emits
toxic fumes of arsenic. See also ARSENIC
COMPOUNDS.
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職業ばく露
Arsenic pentoxide is used in production
of metal arsenates; as an herbicide, defoliant on cotton;
as a chemical intermediate; as an ingredient in wood preservatives;
and in glass. Other possible uses are as an insecticide
and soil sterilant.
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貯蔵
Arsenic pentoxide should be kept stored separately from strong bases, reducing substances, food, and feedstuffs and dry and safe area.
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輸送方法
UN1559 Arsenic pentoxide, Hazard Class: 6.1;
Labels: 6.1-Poisonous materials.
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不和合性
Decomposes above 315 C, forming oxygen
and arsenic trioxide fumes. Arsenic pentoxide is an
oxidizer; reacts violently with bromine pentafluoride and
reducing agents. The solution in water is a weak acid.
Incompatible with acids, strong alkalis; halogens, rubidium
carbide, zinc. Corrosive to metals in the presence of moisture.
Contact with acids or acid mists releases deadly arsine
gas.
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廃棄物の処理
Dissolve in a minimum of
concentrated hydrochloric acid. Dilute with water until
white precipitate forms. Add HCl to dissolve. Saturate with
H2S; filter and wash precipitate and return to supplier.
Alternatively, precipitate with heavy metals, such as lime
or ferric hydroxide in lieu of H2S. If needed, seek
professional environmental engineering assistance from
the United States Environmental Protection Agency
Environmental Response Team at (908) 548-8730 (24-hour
response line). Consult with environmental regulatory agencies
for guidance on acceptable disposal practices.
Generators of waste containing this contaminant (≥100 kg/
mo) must conform with EPA regulations governing storage,
transportation, treatment, and waste disposal. In accordance
with 40CFR165, follow recommendations for the disposal
of pesticides and pesticide containers. Must be disposed
properly by following package label directions or by contacting your local or federal environmental control
agency, or by contacting your regional EPA office.
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予防処置
During handling and use of arsenic pentoxide, occupational workers should use protective
gloves, protective clothing, safety goggles or eye protection in combination with breathing protection if using powder, and workers should not eat, drink, or smoke in the area. The worker should NOT wash away the spillage/waste into the sewer. The containers of
arsenic pentoxide may explode when heated
