ChemicalBook > Product Catalog > Inorganic chemistry > Inorganic salts > Inorganic ammonium salts > Ammonium dichromate
Ammonium dichromate Chemical Properties
- Melting point:170 °C (dec.)(lit.)
- Density 2.150
- vapor density 8.7 (vs air)
- solubility H2O: 1 M at 20 °C, clear, colorless
- form Solid
- color Orange to red
- PH Range3 - 4
- Water Solubility 360 g/L (20 ºC)
- Decomposition 170 °C
- Merck 14,515
- Stability:Stability Strong oxidizer - contact with flammable materials may cause fire. Reactions carried out in closed vessels may lead to explosion. Incompatible with organic materials, strong reducing agents.
- CAS DataBase Reference7789-09-5(CAS DataBase Reference)
- EPA Substance Registry SystemAmmonium dichromate(VI) (7789-09-5)
- Hazard Codes E,T+,N
- Risk Statements 45-46-60-61-2-8-21-25-26-34-42/43-48/23-50/53
- Safety Statements 53-45-60-61
- RIDADR UN 1439 5.1/PG 2
- WGK Germany 3
- RTECS HX7650000
- Autoignition Temperature218°C
- TSCA Yes
- HazardClass 5.1
- PackingGroup II
- HS Code 28415000
- Hazardous Substances Data7789-09-5(Hazardous Substances Data)
- ToxicityLDLo scu-gpg: 25 mg/kg EQSSDX 1,1,75
Ammonium dichromate Usage And Synthesis
- DescriptionAmmonium dichromate is a salt consisting of ammonium ions and dichromate ions. It can be used as in pyrotechinics, photography as well as lithography. It can be used as a catalyst and a source of pure nitrogen in the laboratory. It can also be used as the mordant of dyeing pigment. It has application in the manufacturing of alizarin, chrome alum, leather tanning and oil purification. Moreover, it can be used for the production of phosphor raster of television screen through acting as the photoactive site. Finally, there are also reports using it for combustion synthesis of perovskite LnCrO3 powder and oxidation of hydroquinones, catechols and phenols.
- ReferencesHavard, Jennifer M., et al. "Design of Photoresists with Reduced Environmental Impact. 1. Water-Soluble Resists Based on Photo- Cross-Linking of Poly(vinyl alcohol)." Plos One 8.4(1999):-.
Kingsley, J. J., and L. R. Pederson. "Combustion synthesis of perovskite LnCrO3 powders using ammonium dichromate." Materials Letters 18.1-2 (1993): 89-96.
Fischer, Alfred, and George N. Henderson. "Oxidation of hydroquinones, catechols, and phenols using ceric ammonium nitrate and ammonium dichromate coated on silica: an efficient and convenient preparation of quinones." Synthesis 1985.6/7 (1985): 641 -643.
Suzuki, S. "Determination of Chromium Atom Density on Deep UV Exposed Ammonium-Dichromated Gelatin Films with Ultraviolet Absorption Spectra." Journal of the Electrochemical Society135.10 (1988):2615-2620.
- Chemical Propertiesbright orange-red crystals
- Chemical PropertiesAmmonium dichromate is a combustible, orange-red crystalline solid which is used in solution.
- OccurrenceBright orange-red monoclinic crystals; odorless; hygroscopic; decomposes at 180°C; density 2.115 g/cm3 at 25°C; readily dissolves in water (26.67 g/100 g at 20°C).
- UsesYellow needles made by chromic acid acting on ammonium hydroxide. The product is produced by crystallization. Ammonium dichromate was used interchangeably with potassium dichromate for sensitizing gelatin, albumen, gums, and other colloids that were used for pigment processes. Ammonium dichromate is more sensitive than the potassium alternative.
- UsesIt is used in oxidimetric standard.
- UsesSource of pure nitrogen (esp in the laboratory); in pyrotechnics (Vesuvius fire); in lithography and photo engraving; in special mordant, catalysts, and porcelain finishes; intermediate in the manufacture of pigments; of magnetic recording materials.
- General DescriptionAmmonium 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.
- Air & Water ReactionsWater soluble.
- Reactivity ProfileAmmonium 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].
- HazardDusts 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.
- Health HazardInhalation 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.
- Safety ProfileConfirmed human carcinogen. Poison by inhalation, ingestion, skin contact, and subcutaneous routes. See also CHROMIUM COMPOUNDS. An unstable oxidizer. Moderately flammable; reacts with reducing agents.
- Potential ExposureIt is used in dyeing, leather tanning and to make fireworks and chromic oxide; in lithography and photoengraving; in manufacture of special mordants and catalysts.
- ShippingUN1439 Ammonium dichromate, Hazard Class: 5.1; Labels: 5.1-Oxidizer.
- Purification MethodsIt crystallises from weak aqueous HCl (ca 1mL/g). It decomposes rapidly on heating. (Possible carcinogen and is POISONOUS)
- IncompatibilitiesAn 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.
- Waste DisposalConsult 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.
Ammonium dichromate Preparation Products And Raw materials
- SODIUM DICHROMATE Chromium(III) oxide Dichromate, Ion chromatography standard solution, Specpure, Cr2O7ˉ2 1000μg/ml Ammonium sulfate Ammonium nitrate DICHROMATE IMIDAZOLIUM DICHROMATE QUINOLINIUM DICHROMATE Pyridinium dichromate Bis(tetrabutylammonium) dichromate TETRAKIS(PYRIDINE)SILVER(I) DICHROMATE 4-CARBOXYPYRIDINIUM DICHROMATE Ammonium dichromate Ammonium carbonate Ammonium chloride Molybdic acid Ammonium formate Sodium dichromate dihydrate
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