Names | |||
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Preferred IUPAC name Chromium(VI) dichloride dioxide | |||
Systematic IUPAC name Dichloridodioxidochromium | |||
Other names Chromic acid chloride Chromium oxychloride Chlorochromic anhydride Chromic oxychloride Chromium chloride oxide Chromium dioxide dichloride Chromium dioxychloride Chromium oxychloride | |||
Identifiers | |||
3D model (JSmol) | |||
ChEBI | |||
ChemSpider | |||
ECHA InfoCard | 100.035.491 | ||
EC Number |
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2231 | |||
PubChem CID | |||
RTECS number |
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UNII | |||
UN number | 1758 | ||
CompTox Dashboard (EPA) | |||
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Properties | |||
CrO2Cl2 | |||
Molar mass | 154.9008 g/mol | ||
Appearance | Blood-red fuming liquid, similar to bromine | ||
Odor | Musty, burning, acrid [1] | ||
Density | 1.911 g/mL, liquid | ||
Melting point | −96.5 °C (−141.7 °F; 176.7 K) | ||
Boiling point | 118.5 °C (245.3 °F; 391.6 K) | ||
Reacts with water | |||
Vapor pressure | 20 mmHg (20 °C) [1] | ||
Hazards | |||
Occupational safety and health (OHS/OSH): | |||
Main hazards | Toxic, oxidizer, carcinogenic, mutagenic, reacts violently with water [1] | ||
GHS labelling: | |||
Danger | |||
H271, H314, H317, H340, H350, H410 | |||
P201, P210, P280, P303+P361+P353, P305+P351+P338+P310, P308+P313 [2] | |||
NFPA 704 (fire diamond) | |||
Flash point | noncombustible [1] | ||
NIOSH (US health exposure limits): | |||
PEL (Permissible) | none [1] | ||
REL (Recommended) | Ca TWA 0.001 mg Cr(VI)/m3 [1] | ||
IDLH (Immediate danger) | N.D. [1] | ||
Safety data sheet (SDS) | Sigma Aldrich - Chromyl Chloride | ||
Related compounds | |||
Related compounds | SO2Cl2; VOCl3; MoO2Cl2; WO2Cl2; CrO2F2 | ||
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
Chromyl chloride is an inorganic compound with the formula CrO2Cl2. It is a reddish brown compound that is a volatile liquid at room temperature, which is unusual for transition metal compounds.
Chromyl chloride can be prepared by the reaction of potassium chromate or potassium dichromate with hydrogen chloride in the presence of sulfuric acid, followed by distillation. [3] [4]
The sulfuric acid serves as the dehydration agent. It can also be prepared directly by exposing chromium trioxide to anhydrous hydrogen chloride gas.
The method used to prepare chromyl chloride is the basis for a qualitative test for chloride: a sample suspected of containing chloride is heated with a mixture of potassium dichromate and concentrated sulfuric acid. If chloride is present, chromyl chloride forms as evidenced by red fumes of CrO2Cl2. Analogous compounds are not formed with fluorides, bromides, iodides and cyanides.
The chromyl chloride test involves heating a sample suspected to contain chlorides with potassium dichromate and concentrated sulfuric acid. If a chloride is present, chromyl chloride forms, its presence being indicated by the formation of red smoke. Otherwise, no red smoke will obviously appear. No similar compound is formed in the presence of fluoride, bromide, iodide, or cyanide, making this test specific to chlorides.
Chromyl chloride oxidizes internal alkenes to alpha-chloroketones or related derivatives. [5] It will also attack benzylic methyl groups to give aldehydes via the Étard reaction. Dichloromethane is a suitable solvent for these reactions. [6]
CrO2Cl2 can also be used to test for the absence of nitrate ions.
Chromyl chloride is severely corrosive and easily burns the skin and eyes. [7]
In chemistry, a salt is a chemical compound consisting of an ionic assembly of positively charged cations and negatively charged anions, which results in a compound with no net electric charge. A common example is table salt, with positively charged sodium ions and negatively charged chloride ions.
Chromic acid is an inorganic acid composed of the elements chromium, oxygen, and hydrogen. It is a dark, purplish red, odorless, sand-like solid powder. When dissolved in water, it is a strong acid. There are 2 types of chromic acid: molecular chromic acid with the formula H
2CrO
4 and dichromic acid with the formula H
2Cr
2O
7.
Cyanogen chloride is a highly toxic chemical compound with the formula CNCl. This linear, triatomic pseudohalogen is an easily condensed colorless gas. More commonly encountered in the laboratory is the related compound cyanogen bromide, a room-temperature solid that is widely used in biochemical analysis and preparation.
Hydrogen bromide is the inorganic compound with the formula HBr. It is a hydrogen halide consisting of hydrogen and bromine. A colorless gas, it dissolves in water, forming hydrobromic acid, which is saturated at 68.85% HBr by weight at room temperature. Aqueous solutions that are 47.6% HBr by mass form a constant-boiling azeotrope mixture that boils at 124.3 °C. Boiling less concentrated solutions releases H2O until the constant-boiling mixture composition is reached.
Potassium dichromate, K2Cr2O7, is a common inorganic chemical reagent, most commonly used as an oxidizing agent in various laboratory and industrial applications. As with all hexavalent chromium compounds, it is acutely and chronically harmful to health. It is a crystalline ionic solid with a very bright, red-orange color. The salt is popular in laboratories because it is not deliquescent, in contrast to the more industrially relevant salt sodium dichromate.
Praseodymium(III) chloride is the inorganic compound with the formula PrCl3. Like other lanthanide trichlorides, it exists both in the anhydrous and hydrated forms. It is a blue-green solid that rapidly absorbs water on exposure to moist air to form a light green heptahydrate.
Classical qualitative inorganic analysis is a method of analytical chemistry which seeks to find the elemental composition of inorganic compounds. It is mainly focused on detecting ions in an aqueous solution, therefore materials in other forms may need to be brought to this state before using standard methods. The solution is then treated with various reagents to test for reactions characteristic of certain ions, which may cause color change, precipitation and other visible changes.
Chromium(III) chloride (also called chromic chloride) is an inorganic chemical compound with the chemical formula CrCl3. It forms several hydrates with the formula CrCl3·nH2O, among which are hydrates where n can be 5 (chromium(III) chloride pentahydrate CrCl3·5H2O) or 6 (chromium(III) chloride hexahydrate CrCl3·6H2O). The anhydrous compound with the formula CrCl3 are violet crystals, while the most common form of the chromium(III) chloride are the dark green crystals of hexahydrate, CrCl3·6H2O. Chromium chlorides find use as catalysts and as precursors to dyes for wool.
Thionyl chloride is an inorganic compound with the chemical formula SOCl2. It is a moderately volatile, colourless liquid with an unpleasant acrid odour. Thionyl chloride is primarily used as a chlorinating reagent, with approximately 45,000 tonnes per year being produced during the early 1990s, but is occasionally also used as a solvent. It is toxic, reacts with water, and is also listed under the Chemical Weapons Convention as it may be used for the production of chemical weapons.
Chromium(III) fluoride is an inorganic compound with the chemical formula CrF3. It forms several hydrates. The compound CrF3 is a green crystalline solid that is insoluble in common solvents, but the hydrates [Cr(H2O)6]F3 (violet) and [Cr(H2O)6]F3·3H2O (green) are soluble in water. The anhydrous form sublimes at 1100–1200 °C.
Trimethylsilyl chloride, also known as chlorotrimethylsilane is an organosilicon compound, with the formula (CH3)3SiCl, often abbreviated Me3SiCl or TMSCl. It is a colourless volatile liquid that is stable in the absence of water. It is widely used in organic chemistry.
Benzyl chloride, or α-chlorotoluene, is an organic compound with the formula C6H5CH2Cl. This colorless liquid is a reactive organochlorine compound that is a widely used chemical building block.
Chromium(II) chloride describes inorganic compounds with the formula CrCl2(H2O)n. The anhydrous solid is white when pure, however commercial samples are often grey or green; it is hygroscopic and readily dissolves in water to give bright blue air-sensitive solutions of the tetrahydrate Cr(H2O)4Cl2. Chromium(II) chloride has no commercial uses but is used on a laboratory-scale for the synthesis of other chromium complexes.
Arsenic trichloride is an inorganic compound with the formula AsCl3, also known as arsenous chloride or butter of arsenic. This poisonous oil is colourless, although impure samples may appear yellow. It is an intermediate in the manufacture of organoarsenic compounds.
Chromium is a member of group 6, of the transition metals. The +3 and +6 states occur most commonly within chromium compounds, followed by +2; charges of +1, +4 and +5 for chromium are rare, but do nevertheless occasionally exist.
Potassium chlorochromate is an inorganic compound with the formula KCrO3Cl. It is the potassium salt of chlorochromate, [CrO3Cl]−. It is a water-soluble orange compound is used occasionally for oxidation of organic compounds. It is sometimes called Péligot's salt, in recognition of its discoverer Eugène-Melchior Péligot.
The Jones oxidation is an organic reaction for the oxidation of primary and secondary alcohols to carboxylic acids and ketones, respectively. It is named after its discoverer, Sir Ewart Jones. The reaction was an early method for the oxidation of alcohols. Its use has subsided because milder, more selective reagents have been developed, e.g. Collins reagent.
Chromyl fluoride is an inorganic compound with the formula CrO2F2. It is a violet-red colored crystalline solid that melts to an orange-red liquid.
Chromium(II) fluoride is an inorganic compound with the formula CrF2. It exists as a blue-green iridescent solid. Chromium(II) fluoride is sparingly soluble in water, almost insoluble in alcohol, and is soluble in boiling hydrochloric acid, but is not attacked by hot distilled sulfuric acid or nitric acid. Like other chromous compounds, chromium(II) fluoride is oxidized to chromium(III) oxide in air.