We unleash your business potential by maximize the business innovation.
Send EmailSodium chromate, chromate of soda, DISODIUM CHROMATE, chromium sodium oxide, CHROMIC ACID DISODIUM SALT, 7775-11-3, 12680-48-7
Sodium chromate
CAS: 7775-11-3;12680-48-7
Molecular Formula: CrNa2O4
Names and Identifiers
| Name | Sodium chromate |
| Synonyms | chromateofsoda Sodium chromate DISODIUM CHROMATE chromiumsodiumoxide chromiumdisodiumoxide CHROMIC ACID DISODIUM SALT Chromicacid(H2CrO4)disodiumsalt SodiumChromate(Tetrahydrate)E.P. chromicacid(h2cro4),disodiumsalt SODIUM CHROMATE ANHYDROUS, EXTRA PURE chromium, dihydroxydioxo-, monosodium salt |
| CAS | 7775-11-3 12680-48-7 |
| EINECS | 231-889-5 |
| InChI | InChI=1/Cr.Na.2H2O.2O/h;;2*1H2;;/q+2;;;;;/p-2/rCrH2O4.Na/c2-1(3,4)5;/h2-3H |
7775-11-3 - Physico-chemical Properties
| Molecular Formula | CrNa2O4 |
| Molar Mass | 161.97324 |
| Density | 2,72 g/cm3 |
| Melting Point | 792°C |
| Water Solubility | 530 G/L (20 ºC) |
| Appearance | Solid |
| Color | Yellow |
| Exposure Limit | ACGIH: TWA 0.0002 mg/m3; STEL 0.0005 mg/m3 (Skin)OSHA: Ceiling 0.1 mg/m3NIOSH: IDLH 15 mg/m3; TWA 0.0002 mg/m3 |
| Merck | 14,8601 |
| Physical and Chemical Properties |
yellow translucent triclinic crystal or crystalline powder. melting point 792°C |
| Use | Mainly used in ink, printing and dyeing, paint pigments, tanning, metal corrosion inhibitors, the manufacture of other chromium salts, organic synthetic oxidants and chemical reagents |
7775-11-3 - Risk and Safety
| Risk Codes | R45 - May cause cancer R46 - May cause heritable genetic damage R60 - May impair fertility R61 - May cause harm to the unborn child R21 - Harmful in contact with skin R25 - Toxic if swallowed R26 - Very Toxic by inhalation R34 - Causes burns R42/43 - May cause sensitization by inhalation and skin contact. R48/23 - R50/53 - Very toxic to aquatic organisms, may cause long-term adverse effects in the aquatic environment. |
| Safety Description | S53 - Avoid exposure - obtain special instructions before use. S45 - In case of accident or if you feel unwell, seek medical advice immediately (show the label whenever possible.) S60 - This material and its container must be disposed of as hazardous waste. S61 - Avoid release to the environment. Refer to special instructions / safety data sheets. |
| UN IDs | UN 3288 6.1/PG 2 |
| WGK Germany | 3 |
| RTECS | GB2955000 |
| TSCA | Yes |
| HS Code | 28415000 |
| Hazard Class | 6.1 |
| Packing Group | II |
7775-11-3 - Upstream Downstream Industry
| Raw Materials | Sodium Dichromate |
7775-11-3 - Nature
Open Data Verified Data
anhydrous sodium chromate is a yellow powder crystal. The relative density is 2. 723 and the melting point is 792 ℃. Soluble in water, aqueous solution is alkaline. Sodium chromate in 19. Under 52 ℃, decahydrate crystallized from aqueous solution, which is monoclinic crystal with relative density of 1. 483, very easy to absorb moisture, and unstable; In 19. Crystallization of the hexahydrate, nzcr04 · 6HzO, from 52 to 26.6; In 26. The tetrahydrate was crystallized at 6~62.8 ℃ to give rise to Naz Cr04-4Hz 0, and an anhydrous orthorhombic crystal of a-Naz Cr04 was formed above 62.8 ℃; at 413 °c it is converted to p-Naz Cr04 in the hexagonal system with a melting point of 792 °c.
Last Update：2024-01-02 23:10:35
7775-11-3 - Preparation Method
Open Data Verified Data
sodium dichromate mother liquor was added to an alkaline solution of sodium chromate for neutralization. Obtained by filtration, clarification, cooling and separation.
Last Update：2022-01-01 08:52:54
7775-11-3 - Use
Open Data Verified Data
chromate is one of the most effective corrosion inhibitors, used as corrosion inhibitor of circulating cooling water system, the corrosion inhibition rate can reach more than 95%. It is usually used in combination with corrosion inhibitors such as phosphate, zinc salt and polyacrylamide. In the cooling water treatment, when the sodium chromate with high mass fraction (250 ~ 700mg/kg) used alone, the steel corrosion effect is excellent.
Last Update：2022-01-01 08:52:55
7775-11-3 - Safety
Open Data Verified Data
hexavalent chromium compounds and their salts were the most toxic among chromium compounds, and the LDso of subcutaneous injection in rabbits was 243mg/kg. The maximum allowable concentration of chromate (sodium, potassium) dust in the air of the production environment is 0.1 mg/ma. Chromate stains the skin, can cause skin itching, produce red pimples or herpes, and the formation of ulcers, mucous membranes will be seriously damaged. Staff should be protected.
Last Update：2022-01-01 08:52:55
7775-11-3 - Reference Information
| EPA chemical substance information | information provided by: ofmpeb.epa.gov (external link) |
| purpose | used as general analytical reagent, oxidant, rust inhibitor, tanning agent and mordant, also used in organic synthesis mainly used in ink, printing and dyeing, paint pigments, tanning, metal corrosion inhibitors, the manufacture of other chromium salts, organic synthetic oxidants and chemical reagents, such as |
| production method | 1. Neutralization method is used. The sodium dichromate alkaline solution was added to the neutralizer. Then add sodium dichromate mother liquor for neutralization reaction, after filtration, clarification, cooling crystallization, prepared sodium chromate product. Chromite (Fe, Mg)O ·(Cr, Al, Fe)2O3 is used as raw material to decompose ore with alkali in the presence of strong oxidant. The oxidation roasting was carried out in a tube furnace at a temperature of 1100 to 1200 °c. The formation of sodium chromate begins when the charge is heated to a not too high temperature (600-800 °c). The rate of formation of sodium chromate increases when the temperature increases to approximately 1000 °c. The reaction principle can be approximated by the following equation. The by-products produced in the reaction process (sodium ferrous acid, sodium aluminate and sodium silicate) react with chromite, lime and oxygen to form sodium chromate and insoluble calcium compounds, therefore, the yield of this method is high (75% ~ 81%). An improved method is that the chromite and the additive calcium oxide are calcined at 1000 ℃ to form calcium chromate chromate (CaO · 4 CrO3 · Cr2O3), and then soda ash is added, it is allowed to react with calcium chromate chromate at 600-700 ° C. To form sodium chromate and a small amount of other by-products. Water leaching treatment, and then to the aqueous solution into CO2, the formation of Ca(OH)2 into CaCO3 precipitation, and the formation of CaCrO4 and soda ash reaction to generate NaCrO. |
