18540-29-9 Usage
Description
Chromium(+6) cation, also known as hexavalent chromium, is a highly reactive and toxic form of chromium. It is a strong oxidizing agent and is highly corrosive. In the environment, chromium(VI) compounds are generally reduced to chromium(III) compounds. The most common chromium(VI) compounds encountered in industry include calcium chromate, chromium trioxide, sodium chromate and dichromate, potassium chromate and dichromate, lead chromate, strontium chromate, and zinc chromate.
Uses
Used in Steel Industry:
Chromium(+6) cation is used as an additive in the steel industry for stainless and heat-resisting steel, providing corrosion resistance and enhancing the mechanical properties of the steel.
Used in Chemical Industry:
Chromium(+6) cation is used as a corrosion inhibitor, in the manufacture of pigments, in metal finishing and chrome plating, in stainless steel production, in leather tanning, and in wood preservatives.
Used in Wood Preservative Industry:
Chromium(+6) cation is used as a component in wood preservatives, providing protection against decay and insects.
Used in Textile Industry:
Chromium(+6) cation is used in textile-dyeing processes, providing colorfastness and improving the quality of the dyed fabrics.
Used in Paint and Ink Industry:
Chromium(+6) cation is used in the production of paints, inks, and pigments, offering color stability and durability.
Used in Battery Industry:
Calcium chromate, a chromium(+6) compound, is used as a corrosion inhibitor and as a depolarizer in batteries.
Used in Metal Treatment:
Chromium(+6) cation is used in metal treatments, such as chrome plating and other metal finishing processes, to improve the appearance and durability of metal surfaces.
Used in Drilling Muds:
Chromium(+6) cation is used in drilling muds to provide corrosion inhibition and improve the performance of the drilling process.
Used in Water Treatment:
Chromium(+6) cation is used in water treatment processes, such as cooling water systems, to prevent corrosion and fouling.
Used in Pyrotechnics:
Strontium chromate, a chromium(+6) compound, is used as a colorant in pyrotechnics, providing bright and vivid colors in various pyrotechnic applications.
Used in Chrome Plating:
Chromium trioxide, a chromium(+6) compound, is used in chrome plating to provide a protective and decorative coating on various metal surfaces.
Used in Production of Catalysts:
Chromium(+6) cation is used in the production of catalysts, which are essential for various chemical reactions and processes.
Carcinogenicity
Chromium hexavalent (VI) compounds are known to be human carcinogens based on sufficient evidence of carcinogenicity from studies in humans.
Check Digit Verification of cas no
The CAS Registry Mumber 18540-29-9 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 1,8,5,4 and 0 respectively; the second part has 2 digits, 2 and 9 respectively.
Calculate Digit Verification of CAS Registry Number 18540-29:
(7*1)+(6*8)+(5*5)+(4*4)+(3*0)+(2*2)+(1*9)=109
109 % 10 = 9
So 18540-29-9 is a valid CAS Registry Number.
InChI:InChI=1/Cr/q+4
18540-29-9Relevant articles and documents
Simultaneous determination of Cr(III) and Cr(VI) in tannery wastewater using low pressure ion chromatography combined with flow injection spectrophotometry
Chen, Shujuan,Zhang, Xinshen,Yu, Lingyun,Wang, Li,Li, Hui
, p. 49 - 55 (2012)
Trivalent and hexavalent chromium have been successfully separated and determined using low pressure ion chromatography combined with flow injection spectrophotometric analysis (LPIC-FIA). A column packed with crosslinking starch microspheres was used for on-line separation of Cr(III) from Cr(VI) in a flow-injection system because of its absorptive effect on Cr(III). To determine the concentration of Cr(III) and Cr(VI) in samples, we used 3.0 mmol/L nitric acid to elute adsorbed Cr(III) from the column and then used ceric sulfate-sulfuric acid as oxidant to convert all Cr(III) into Cr(VI). Then, Cr(VI) directly came from the samples and Cr(VI) came from Cr(III) successively formed a amaranthine complex with diphenycarbazide and the complex shows a maximum absorption at 530 nm. Analytical parameters including the concentration of eluent and oxidant solution, oxidizing temperature, length of oxidizing reaction coil, reaction coil and injection coil, interfering effects, etc., were optimized. The limit of detection was 1.25 μg/L for Cr(VI) and 3.76 μg/L for Cr(III). The linear relationship between absorption with the concentration of Cr(VI) and Cr(III) was 0.001-1.000 mg/L and 0.030-1.000 mg/L with correlation coefficients of 0.9995 and 0.9994, respectively. The relative standard deviation of Cr(VI) and Cr(III) was 1.21% and 1.66%, respectively (n = 10). Major cations and anions did not show any interference. We validated this method through certified reference materials and through measuring the recovery in tannery wastewater.
Oxidation of chromium (III) by periodate in aqueous alkaline medium - A kinetic study
Hiremath,Tuwar,Nandibewoor
, p. 61 - 64 (2007/10/03)
The kinetics of oxidation of chromium(III) by periodate in aqueous alkaline medium at 27°C obeys the rate law where K1 is dissociation constant of the equilibrium H3IO62- ? H2IO63-+H+, k1 and k2 are the rate constants for the slow steps of the reactions H2IO63-- Cr(OH)4- and H3IO62-- Cr(OH)4- respectively. The constants k1 and k2 are calculated and used to regenerate the experimental rate constants at various conditions.
Kinetics and mechanism of silver (I) catalysed oxidation of chromium (III) by peroxidiphosphate in acetate buffers
Parashar, Pradeep,Sharma, P. D.,Gupta, Y. K.
, p. 383 - 386 (2007/10/02)
In the title reaction the rate is independent of the and occurs by the redox cycle Ag(I)/Ag(II) through four steps: H2P2O82- + Ag+ (k1); H2P2O82- + AgO2CCH3 (k'1); HP2O83- + Ag+ (k2); HP2O83- + AgO2CCH3 (k'2). k1, k'1, k2 and k'2 (dm3mol-1s-1) are 0.017, 0.069, 0.19 and 0.36, respectively at 40 deg and ionic strength = 1.0 mol dm-3.
