Chromium

Base Information

• Chemical Name: Chromium
• CAS No.: 7440-47-3
• Deprecated CAS: 188785-87-7,195161-82-1,195161-82-1
• Molecular Formula: Cr
• Molecular Weight: 51.996
• Hs Code.: 8112210000
• European Community (EC) Number: 231-157-5
• ICSC Number: 0029
• UN Number: 1759,3089
• UNII: 0R0008Q3JB
• DSSTox Substance ID: DTXSID3031022,DTXSID401315238
• Nikkaji Number: J3.732J
• Wikipedia: Chromium
• Wikidata: Q725,Q27115184
• NCI Thesaurus Code: C370
• Mol file: 7440-47-3.mol

Synonyms:Chromium

Chemical Property of Chromium

Chemical Property:

• Appearance/Colour: silver-gray solid
• Melting Point: 1890 ºC
• Boiling Point: 2200 ºC
• Flash Point: 50 °F
• PSA: 0.00000
• Density: 7.20℃
• LogP: 0.00000
• Storage Temp.: Storage temperature: no restrictions.
• Water Solubility.: Insoluble in water.
• Hydrogen Bond Donor Count: 0
• Hydrogen Bond Acceptor Count: 0
• Rotatable Bond Count: 0
• Exact Mass: 51.940505
• Heavy Atom Count: 1
• Complexity: 0
• Transport DOT Label: Corrosive

Purity/Quality:

99.9% ^*data from raw suppliers

Chromium foil, light tested, 25x25mm, thickness 0.015mm, permanent polyester support, 99.99+% ^*data from reagent suppliers

Safty Information:

• Hazard Codes: F,C,Xn,Xi
• Statements: 11-20/21/22-34-40-23-67-36
• Safety Statements: 16-26-36/37/39-45-36/37-27

MSDS Files:

SDS file from LookChem

Total 1 MSDS from other Authors

Useful:

• Chemical Classes: Metals -> Chromium Compounds, Inorganic
• Canonical SMILES: [Cr]
• Recent ClinicalTrials: Effects of a Dietary Supplement on Markers of Glucose Control and Quality of Life
• Recent NIPH Clinical Trials: To quantify the effect of excimer laser angioplasty in patients with acute heart attack for salvaging the cardiac muscle.
• Inhalation Risk: A harmful concentration of airborne particles can be reached quickly when dispersed.
• Effects of Short Term Exposure: May cause mechanical irritation to the eyes and respiratory tract.
• Physical Properties: Hard blue-white metal; body-centered cubic crystal; density 7.19 g/cm3; melts at 1,875°C; vaporizes at 2,199°C; electrical resistivity at 20°C, 12.9 microhm–cm; magnetic susceptibility at 20°C, 3.6x10–6 emu; standard electrode potential 0.71 V (oxidation state 0 to +3).
• Description: Chromium as a metallic element was first discovered over 200 years ago, in 1797. But the history of chromium really began several decades before this. In 1761, in the Beresof Mines of the Ural Mountains, Johann Gottlob Lehmann obtained samples of an orange-red mineral, which he called ‘Siberian red lead.’ He analyzed this mineral in 1766 and discovered that it contained lead “mineralized with a selenitic spar and iron particles.” The mineral he found was crocoite, a lead chromate (PbCrO4).
• Physical properties: Chromium is a silvery white/gray, hard, brittle noncorrosive metal that has chemical andphysical properties similar to the two preceding elements in period 4 (V and Ti). As one of thetransition elements, its uses its M shell rather than its outer N shell for valence electrons whencombining with other elements. Its melting point is 1,857°C, its boiling point is 2,672°C,and its density is 7.19 g/cm3.
• Uses: In manufacture of chrome-steel or chrome-nickel-steel alloys (stainless steel), nonferrous alloys, heat resistant bricks for refractory furnaces. To greatly increase strength, hardness and resistance of metals to abrasion, corrosion and oxidation. For chrome plating of other metals; leather tanning; as pigment and mordant; wood preservative. Use of 51Cr as diagnostic aid see sodium chromate(VI). Chromium is used in the manufacture ofits alloys, such as chrome-steel or chromenickel-steel. It is also used for chromeplatingof other metals, for tanning leather,and in catalysts. It occurs in chromite ores(FeO·Cr2O3). The best-known use of chromium is for the plating of metal and plastic parts to producea shiny, reflective finish on automobile trim, household appliances, and other items where abright finish is considered attractive. It also protects iron and steel from corrosion.It is used to make alloys, especially stainless steel for cookware, and items for whichstrength and protection from rusting and high heat are important.Its compounds are used for high-temperature electrical equipment, for tanning leather, asa mordant (fixes the dyes in textiles so that they will not run), and as an antichalking agentfor paints.Some research has shown that, even though most chromium compounds are toxic, a smalltrace of chromium is important for a healthy diet for humans. A deficiency produces diabeteslike symptoms, which can be treated with a diet of whole-grain cereal, liver, and brewer’s yeast.Chromium’s most important radioisotope is chromium-51, which has a half-life of about27 days. It is used as a radioisotope tracer to check the rate of blood flowing in constrictedarteries.Some chromium compounds (e.g., chromium chloride, chromic hydroxide, chromic phosphate) are used as catalysts for organic chemical reactions.In 1960 the first ruby laser was made from a ruby crystal of aluminum oxide (Al2O3). Thesecrystals contain only a small amount of chromium, which stores the energy and is responsiblefor the laser action. A small amount of chromium found in the mineral corundum is responsible for the bright red color of the ruby gemstone.

Technology Process of Chromium

There total 241 articles about Chromium which guide to synthetic route it. The literature collected by LookChem mainly comes from the sharing of users and the free literature resources found by Internet computing technology. We keep the original model of the professional version of literature to make it easier and faster for users to retrieve and use. At the same time, we analyze and calculate the most feasible synthesis route with the highest yield for your reference as below:

synthetic route:

Reference yield: 94.2%

chromium(III) chloride (10025-73-7,16284-59-6) + magnesium (7439-95-4) → chromium (7440-47-3)

Guidance literature:

With potassium chloride; sodium chloride; byproducts: MgCl2; 12 kg CrCl3, 3.5 kg Mg, 17.6 kg KCl and 12.4 kg NaCl mixed then heated in electric furnace at 800°C; formed MgCl2 dissolved and filtrated, remainder washed with water twice then with dild. HNO3;

Reference yield:

→ chromium (7440-47-3) + hydrogen (1333-74-0)

Guidance literature:

With thiourea; In water; at 60 ℃; for 2h; Electrolysis;

Reference yield:

chromium(III) oxide + aluminium (7429-90-5) → aluminum oxide (1333-84-2,1344-28-1) + chromium (7440-47-3)

Guidance literature:

redn. of Cr2O3 with Al, formed Al2O3 reduced in electolitically way and used again;

upstream raw materials:

dichromic acid

pyrographite

Downstream raw materials:

ethyl 1-(trifluoromethyl)cyclopropane-1-carboxylate

11β,16α,17α,21-tetrahydroxypregnane-1,4-diene-3,20-dione-21-acetate

N-(phosphonemethyl)glycine

1,2-diamino-benzene