Name | Chromous acid |
Synonyms | Chromous acid Chromium(II) chloride CHROMIUM(II) CHLORIDE FOR SYNTHESIS |
CAS | 10049-05-5 |
EINECS | 233-163-3 |
InChI | InChI=1S/2ClH.Cr/h2*1H;/q;;+2/p-2 |
Molecular Formula | Cl2Cr |
Molar Mass | 122.9 |
Density | 2.9g/mLat 25°C(lit.) |
Melting Point | 824°C(lit.) |
Boling Point | 1120°C (estimate) |
Water Solubility | Soluble in water. Insoluble in alcohol and ether. |
Solubility | It may decompose in water and is insoluble in alcohol and ether. |
Appearance | grayish green powder |
Specific Gravity | 2.878 |
Color | Off-white to green-gray |
Exposure Limit | NIOSH: IDLH 250 mg/m3; TWA 0.5 mg/m3 |
Merck | 14,2244 |
Storage Condition | Store below +30°C. |
Stability | Stable, but decomposes in water or moist air. Incompatible with water, oxidizing agents, active metals. |
Sensitive | Air & Moisture Sensitive |
MDL | MFCD00010947 |
Physical and Chemical Properties | The appearance of chromium chloride was dark green crystalline powder. Soluble in water, soluble in ethanol, insoluble in ether. After boiling with water for a long time into a green solution. Decomposition by heating. In the air, the heat is changed to chromium oxide. Sublimable in a stream of chlorine gas, and co-heating with carbon tetrachloride at 400 °c, a kinetically inert purple anhydrate can be obtained. There are three variants of six water, dark green, light green and purple, which turn into a mixture of dark green and purple in aqueous solution, but appear dark green in organic solvents such as DMSO,DMF, ethanol and so on. |
Use | Used with iodoform and tetraethylenediamine to convert terminal olefins to trans-iodocyclopropane in high yield. For the preparation of bis (indenyl) chromium dimers and related products. Regulate the condensation of aldehydes with trisubstituted chloroolefins. Highly active pre-catalysts required for the synthesis of ethylene oligomerization. Under the action of hydrogen, it is co-reduced with other metal halides to form subdivided metals? Intercompounds, which can be used as structural materials or compounds with effective thermoelectricity, magnetism and oxidation resistance. |
Hazard Symbols | Xn - Harmful |
Risk Codes | R22 - Harmful if swallowed R36/37/38 - Irritating to eyes, respiratory system and skin. |
Safety Description | S26 - In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. S36 - Wear suitable protective clothing. |
WGK Germany | 3 |
RTECS | GB5250000 |
FLUKA BRAND F CODES | 1-10 |
TSCA | Yes |
HS Code | 2827 39 85 |
Toxicity | LD50 orally in rats: 1.87 g/kg (Smyth) |
EPA chemical information | Information provided by: ofmpub.epa.gov (external link) |
use | chromium chloride is used to make chromium salt, chrome plating and mordant, etc. Used with iodoform and tetraethylenediamine to convert terminal olefins to trans-iodocyclopropane in high yield. For the preparation of bis (indenyl) chromium dimers and related products. Regulate the condensation of aldehydes with trisubstituted chloroolefins. Highly active pre-catalysts required for the synthesis of ethylene oligomerization. Under the action of hydrogen, it is co-reduced with other metal halides to form subdivided intermetallic compounds, which can be used as structural materials or compounds with effective thermoelectricity, magnetism and oxidation resistance. |
Production method | 1. The raw material is anhydrous chromium trichloride, sublimated and refined at 800°C in a dry chlorine or hydrogen chloride gas stream. The ferric chloride mixed in it can be removed because it sublimates first at low temperature. The reaction tube can be sealed with one end with a diameter of 25mm and a length of 500mm. Quartz tube or ultra-hard glass tube should be drawn into necking near the outlet for later closure. Install a two-hole silicone rubber plug at the opening, and insert the air duct and exhaust pipe leading to the bottom. The reaction tube is heated to 500 ℃ in advance, and the reaction tube is completely dried under reduced pressure. Place the reaction tube horizontally, lay 5g of sublimated refined anhydrous chromium trichloride CrCl3 on the end of the tube, and then pass oxygen-free hydrogen chloride and hydrogen (1: 1) at a flow rate of 50mL per minute. The mixture. The reaction tube is placed in an electric furnace and heated at 500 ℃, I .e. reduction reaction occurs. Make all the red and purple raw materials turn white and cool, replace the gas in the tube with nitrogen, pull the air duct to the outlet, and then close the reaction tube. 2. Method 1 (The mixture of 10 grams of zinc powder, 0.8 grams of mercury chloride, 10 milliliters of water and 0.5 milliliters of concentrated hydrochloric acid was violently shaken for 5 minutes to pour out the supernatant, leaving zinc amalgam powder. Add another 20 ml of water and 2 ml of concentrated hydrochloric acid, bubble into carbon dioxide gas, so that the mixture can be stirred, and then add 5 grams of chromium chloride in batches to obtain a blue-black solution. Store for use in carbon dioxide gas. Method 2: Dissolve 5g of chromium chloride hexahydrate in 35 ml of absolute ethanol containing 2.0 ml of concentrated hydrochloric acid, and filter it into a 2 x 10cm Jones reduction tube (containing 30 mesh zinc amalgam powder) at a rate of 2 ml per minute in the presence of carbon dioxide gas. The obtained solution was sealed in a glass bottle containing 1 gram of zinc amalgam powder. Method 3: Treat chromium trichloride with hydrogen at red hot temperature to obtain anhydrous chromium chloride |
category | toxic substances |
toxicity classification | poisoning |
acute toxicity | oral-rat LD50: 1870 mg/kg |
flammability hazard characteristics | can be burned; toxic chromium-containing smoke is produced at the fire site; |
storage and transportation characteristics | warehouse low temperature, ventilation, drying |
fire extinguishing agent | water, carbon dioxide, dry powder, sand |
occupational standard | TWA 0.5 mg (chromium)/m3 |
toxic substance data | information provided by: pubchem.ncbi.nlm.nih.gov (external link) |