Hexavalent chromiumHexavalent chromium (chromium(VI), Cr(VI), chromium 6) is any chemical compound that contains the element chromium in the +6 oxidation state (thus hexavalent). It has been identified as carcinogenic, which is of concern since approximately 136,000 tonnes (150,000 tons) of hexavalent chromium were produced in 1985. Hexavalent chromium compounds can be carcinogens (IARC Group 1), especially if airborne and inhaled where they can cause lung cancer.
Sulfuric acidA bottle of 96% pure sulfuric acidNames IUPAC nameSulfuric acidOther names Oil of vitriolHydrogen sulfateDihydrogen sulfateIdentifiers CAS Number7664-93-93D model (JSmol)Interactive imageChEBICHEBI:26836ChEMBLChEMBL572964ChemSpider1086ECHA InfoCard100.028.763EC Number231-639-5E numberE513 (acidity regulators, ...)Gmelin Reference2122 KEGGD05963PubChemCID1118RTECS numberWS5600000UNIIO40UQP6WCFUN number1830 CompTox Dashboard(EPA)DTXSID5029683InChIInChI=1S/H2O4S/c1-5(2,3)4/h(H2,1,2,3,4)Key: QAOWNCQODCNURD-UHFFFAOYSA-NInChI=1/H2O4S/c1-5(2,3)4/h(H2,1,2,3,4)Key: QAOWNCQODCNURD-UHFFFAOYACSMILESOS(=O)(=O)OProperties Chemical formulaH2SO4, sometimes expressed (HO)2SO2Molar mass98.07 g·mol Appearance Colorless viscous liquid OdorOdorless Density1.8302 g/cm, liquid Melting point10.31 °C (50.56 °F; 283.46 K) Boiling point337 °C (639 °F; 610 K) When sulfuric acid is above 300 °C (572 °F; 573 K), it gradually decomposes to SO3 + H2OSolubility in watermiscible, exothermic Vapor pressure0.001 mmHg (20 °C) Acidity (pKa) pKa1 = strongpKa2 = 2.0 Conjugate baseBisulfateViscosity26.7 cP (20 °C) Structure Crystal structuremonoclinic Space groupC2/c Lattice constanta = 818.1(2) pm, b = 469.60(10) pm, c = 856.3(2) pmα = 90°, β = 111.39(3)°, γ = 90°Formula units (Z)4 Thermochemistry Std molarentropy(S298)157 J/(mol·K) Std enthalpy offormation(ΔfH298)−814 kJ/mol Enthalpy of vaporization(ΔfHvap)56 kJ/mol Hazards GHS labelling: PictogramsSignal wordDangerHazard statementsH290, H314Precautionary statementsP260, P264, P280, P301+P330+P331, P303+P361+P353, P304+P340, P305+P351+P338, P310, P321, P363, P405, P501NFPA 704 (fire diamond) 302WOXFlash pointNon-flammable Threshold limit value (TLV)15 mg/m (IDLH), 1 mg/m (TWA), 2 mg/m (STEL) Lethal dose or concentration (LD, LC): LD50 (median dose)2140 mg/kg (rat, oral) LC50 (median concentration)50 mg/m (guinea pig, 8 h)510 mg/m (rat, 2 h)320 mg/m (mouse, 2 h)18 mg/m (guinea pig)LCLo (lowest published)87 mg/m (guinea pig, 2.75 h) NIOSH (US health exposure limits): PEL (Permissible)TWA 1 mg/m REL (Recommended)TWA 1 mg/m IDLH (Immediate danger)15 mg/m Related compounds Related strong acidsSelenic acidHydrochloric acidNitric acidPerchloric acidFluoroantimonic acidChromic acidRelated compoundsSulfurous acidPeroxymonosulfuric acidSulfur trioxideOleumExcept where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).Nverify ( ?)
Cleaning agentCleaning agents or hard-surface cleaners are substances (usually liquids, powders, sprays, or granules) used to remove dirt, including dust, stains, foul odors, and clutter on surfaces. Purposes of cleaning agents include health, beauty, removing offensive odors, and avoiding the spread of dirt and contaminants to oneself and others.
Surface finishingSurface finishing is a broad range of industrial processes that alter the surface of a manufactured item to achieve a certain property. Finishing processes may be employed to: improve product appearance, adhesion or wettability, solderability, corrosion resistance, tarnish resistance, the chemical resistance, the wear resistance, hardness, modify electrical conductivity, remove burrs and other surface flaws, and control the surface friction.
Chromium toxicityChromium toxicity refers to any poisonous toxic effect in an organism or cell that results from exposure to specific forms of chromium—especially hexavalent chromium. Hexavalent chromium and its compounds are toxic when inhaled or ingested. Trivalent chromium is a trace mineral that is essential to human nutrition.
Chromium compoundsChromium compounds are compounds containing the element chromium (Cr). 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. Common oxidation statesChromium(0)Many Cr(0) complexes are known. Bis(benzene)chromium and chromium hexacarbonyl are highlights in organochromium chemistry.
ElectroplatingElectroplating, also known as electrochemical deposition or electrodeposition, is a process for producing a metal coating on a solid substrate through the reduction of cations of that metal by means of a direct electric current.
Chromium–↑Cr↓Movanadium ← chromium → manganeseVapor degreasingVapor degreasing is a surface finishing process. It involves solvents in vapor form to cleanse the workpiece in preparation for further finishing operations.Solvent degreasingSolvent degreasing is a process used to prepare a part for further operations such as electroplating or painting. Typically it uses petroleum, chlorine, dry ice or alcohol based solvents to dissolve the machining fluids and other contaminants that might be on the part.
CorrosionCorrosion is a natural process that converts a refined metal into a more chemically stable oxide. It is the gradual deterioration of materials (usually a metal) by chemical or electrochemical reaction with their environment. Corrosion engineering is the field dedicated to controlling and preventing corrosion.
MetalType of materialIron, shown here as fragments and a 1 cm cube, is an example of a chemical element that is a metal.Metal in the form of a gravy boat made from stainless steel, an alloy largely composed of iron, chromium and nickelA metal (from Ancient Greek μέταλλον (métallon) 'mine, quarry, metal') is a material that, when polished or fractured, shows a lustrous appearance, and conducts electricity and heat relatively well.*As an Amazon Associate I earn from qualifying purchases.