二クロム酸アンモニウム 化学特性,用途語,生産方法
外観
黄赤色～赤褐色、結晶～結晶性粉末又は塊
溶解性
水 (35.56g/100ml 水 20℃), エタノールに易溶。水に溶けやすく、エタノールにやや溶けやすい。
解説
二クロム酸アンモニウム，単斜晶系の橙赤色のイオン結晶．2個の四面体型のCrO4が，1個のO原子を共有して結合したCr2O72－をもつ．Cr-O1.63 Å(末端)，1.78 Å(架橋)．∠Cr-O-Cr121°．密度2.155 g cm－3．185 ℃ で分解する．(NH4)2Cr2O7 → Cr2O3 ＋ N2 ＋ 4H2O水に易溶だが，潮解性はない．水溶液は酸性(1％ 水溶液で，pH 約3.95)を示す．酸化性で，固体塩と有機物との混合物は加熱または衝撃で爆発することがある．
用途
酸化剤、触媒、顔料、メッキ剤。
用途
感光体スクリーン（CRT）の製造
製法
二クロム酸アンモニウム，重クロム酸アンモニウムは慣用名で，現行命名法では正しくない．IUPAC体系名はヘプタオキシド二クロム酸アンモニウム．CrO3を水に溶かし，これに計算量のNH3を加え，濃縮，冷却すると得られる．
応用
酸化剤，触媒，写真製版，染色，花火製造などに使用する．熱分解により酸化クロムCr2O3を製造する．高純度塩は純粋な N2 や金属Crの製造原料となる．
化学的特性
Ammonium dichromate is a combustible,
orange-red crystalline solid which is used in solution.
天然物の起源
Bright orange-red monoclinic crystals; odorless; hygroscopic; decomposes at 180°C; density 2.115 g/cm
3 at 25°C; readily dissolves in water (26.67 g/100 g at 20°C).
使用
Ammonium dichromate is used in photo engraving, dye mordant, pigments, pickling, photography, process engraving, lithography, pyrotechnics, glazes for porcelain and china wares. It acts as a catalyst and a source of nitrogen in the laboratory and as the photoactive site. It is also used in the preparation of alizarin and chrome alum. Further, it is used in leather and oil industry for tanning and purification respectively. It is involved in the production of the phosphor raster television screens and other devices.
一般的な説明
Ammonium dichromate is a bright orange red crystalline solid. Ammonium dichromate is readily ignited and burns producing a voluminous green residue. If heated in a closed container, the container may rupture due to the decomposition of the material. Ammonium dichromate may also act as a strong oxidizing agent if mixed with or contaminated with combustible material. Ammonium dichromate is soluble in water.
空気と水の反応
Water soluble.
反応プロフィール
Ammonium dichromate is an oxidizing reagent, Ammonium dichromate readily reacts with reducing materials, in large quantity Ammonium dichromate may produce a violent reaction. Direct exposure to heat or shock will explode it. When heated to decomposition Ammonium dichromate emits toxic fumes of ammonia and nitrogen oxides [Sax, 9th ed., 1996, p. 205].
危険性
Dusts and solutions are toxic, irritating to
eyes and skin; dangerous fire risk. Strong oxidizing
agent may explode in contact with organic materi-
als. TLV: 0.05 mg(Cr)/m
3
; Confirmed human car-
cinogen.
健康ハザード
Inhalation causes irritation or ulceration of the mucous membranes of the nose, throat or respiratory tract. Respiratory irritation can produce symptoms resembling those of asthma. Continuing irritation of the nose may lead to perforation of the nasal septum. External contact can cause eye irritation and conjunctivitis, irritation and ulceration of skin wounds, and rash or external ulcers. If ingested, irritates mucous membrane and causes vomiting.
安全性プロファイル
Confirmed human carcinogen. Poison by inhalation, ingestion, skin contact, and subcutaneous routes. See also CHROMIUM COMPOUNDS. An unstable oxidizer. Moderately flammable; reacts with reducing agents.
職業ばく露
It is used in dyeing, leather tanning and
to make fireworks and chromic oxide; in lithography and photoengraving;
in manufacture of special mordants and catalysts.
輸送方法
UN1439 Ammonium dichromate, Hazard Class:
5.1; Labels: 5.1-Oxidizer.
純化方法
It crystallises from weak aqueous HCl (ca 1mL/g). It decomposes rapidly on heating. (Possible carcinogen and is POISONOUS)
不和合性
An unstable oxidizer; freezing/melting
point5(decomposes below MP) 180 C; decomposition
becomes self-sustaining and violent at about 225 C. Contact
with combustible, organic or other easily oxidized materials,
strong acids; hydrazine and other reducing agents; alcohols,
sodium nitrite may cause fire and explosions.
廃棄物の処理
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. Add a
large volume of a reductant solution (hypo, bisulfite or ferrous
salt and acidify with sulfuric acid). Neutralize when reduction
is complete and flush to sewer with large volume of water.
二クロム酸アンモニウム 上流と下流の製品情報
原材料
準備製品