Potassium dichromate

What is chrome allergy? Chrome allergy presents with a dermatitis. It is due to a delayed hypersensitivity reaction to chromium salts (chromates), particularly Cr(III) and Cr(VI). Chromium salts are used as an ingredient in the manufacture of many other products such as cement, mortar, leather, paints, and anticorrosives. Although most people associate ‘chrome’ with the bright, shiny and durable finish of chrome-plated metal products, contact with these rarely give rise to chrome allergy. Allergic contact dermatitis due to contact with a metal object is usually caused by Chrome allergy Where are chromium salts found? Most exposure to chromium salts is via the workplace, principally from cement and mortar used in the building industry. There are many other sources of chromates. Home/personal sourcesof chromium salts Examples include: • Chrome-tanned leather goods including • Yellow or green • Disinfecting and bleaching agents • Unlit and charred safety match heads • Green felt fabric used to cover snooker and card tables • Anti-rust primer and in yellow or green paint • Yellow-green tattoo ink • Radiator coolants • Dental or orthopaedic implants. Work sources of chromium salts Allergic cement dermatitis is usually due to dichromates found in cement and is highest amongst workers handling wet cement. Note that cement also causes irritant contact dermatitis. • Primer paints in the automobile industry • Metalworkers and welders of chromium steel alloys • Diesel locomotive radi...

Catalogue Number Availability Packaging Qty/Pack Price Quantity 1048650500 Retrieving availability... — Limited Availability In Stock Discontinued Limited Quantities Available Availability to be confirmed In Stock Limited Availability In Stock Remaining : Will advise Remaining : Will advise Will advise Glass bottle 500 g Retrieving price... Price could not be retrieved Minimum Quantity is a multiple of Maximum Quantity is Upon Order Completion More Information You Saved ( ) — Request Pricing Description Catalogue Number 104865 Synonyms Potassium bichromate, Potassium pyrochromate References Product Information CAS number 7778-50-9 EC index number 024-002-00-6 EC number 231-906-6 Grade ACS,ISO Hill Formula Cr₂K₂O₇ Chemical formula K₂Cr₂O₇ Molar Mass 294.19 g/mol HS Code 2841 50 00 Quality Level Applications Biological Information Physicochemical Information Boiling point >500 °C (1013 hPa) Density 2.680 g/cm3 (20 °C) Melting Point 390 °C pH value 3.5 - 5.0 (29.4 g/l, H₂O, 25 °C) Bulk density 1250 kg/m3 Solubility 115 g/l Dimensions Materials Information Toxicological Information LD 50 oral LD50 Rat 90.5 mg/kg LD 50 dermal LD50 Rat 1170 mg/kg Safety Information according to GHS Hazard Pictogram(s) Hazard Statement(s) H272: May intensify fire; oxidizer. H301: Toxic if swallowed. H312: Harmful in contact with skin. H314: Causes severe skin burns and eye damage. H317: May cause an allergic skin reaction. H330: Fatal if inhaled. H334: May cause allergy or asthma symptoms or brea...

In aqueous solution, chromate and dichromate anions exist in a 2 CrO 2− 4 + 2H + ⇌ Cr 2O 2− 7 + H 2O The Further condensation reactions can occur in strongly acidic solution with the formation of trichromates, Cr 3O 2− 10, and tetrachromates, Cr 4O 2− 13. 4 units sharing corners. The hydrogen chromate ion, HCrO 4 −, is a HCrO − 4 ⇌ CrO 2− 4 + H +; p K a≈5.9 It is also in equilibrium with the dichromate ion: 2 HCrO − 4 ⇌ Cr 2O 2− 7 + H 2O This equilibrium does not involve a change in hydrogen ion concentration, which would predict that the equilibrium is independent of pH. The red line on the predominance diagram is not quite horizontal due to the simultaneous equilibrium with the chromate ion. The hydrogen chromate ion may be protonated, with the formation of molecular 2CrO 4, but the K a for the equilibrium H 2CrO 4 ⇌ HCrO − 4 + H + is not well characterized. Reported values vary between about −0.8 and 1.6. The dichromate ion is a somewhat weaker base than the chromate ion: HCr 2O − 7 ⇌ Cr 2O 2− 7 + H +, p K=1.18 The p K value for this reaction shows that it can be ignored at pH>4. Oxidation–reduction properties [ ] The chromate and dichromate ions are fairly strong 3+ ion is produced. Cr 2O 2− 7 + 14H + + 6e − → 2Cr 3+ + 7H 2O ε 0=1.33V In alkaline solution chromium(III) hydroxide is produced. The CrO 2− 4 + 4 H 2O + 3 e − → Cr(OH) 3 + 5 OH − ε 0=−0.13V Applications [ ] The primary chromium ore is the mixed metal oxide 2O 4, found as brittle metallic black crystals or gr...

It's well known that the chemical element potassium is very important for a wide variety of biological functions in the human body. However, the chemical compound potassium dichromate is quite the opposite - it is very harmful to our health. Potassium dichromate is a chemical compound typically used as an inorganic chemical reagent for industrial and laboratory processes. As we will see, this chemical is used to produce an array of products ranging from shoe polishes and glues to paints and waxes. Potassium dichromate in solid form Commonly used in the laboratory as an analytical reagent, potassium dichromate is also used in industry. For example, the construction industry uses this chemical in cement products to enhance density and texture. Certain woods can change their appearance or color in the presence of potassium dichromate. This is particularly useful when you would like those mahogany wood floors or furniture to show their rich brown colors. Other uses of potassium dichromate include the tanning of leather for footwear, as an oxidizing agent in the photographic printing process, and during the cleaning of glassware or etching of glass materials. As useful and interesting as this compound may be, it's very important to realize potassium dichromate is toxic to our health. This toxicity is dependent on how much you are exposed to in a certain period of time. Just to stress how nasty this chemical is, potassium dichromate is classified as a carcinogen, which is a chem...