How was element chromium discovered?
Chromium was discovered by Louis-Nicholas Vauquelin while experimenting with a material known as Siberian red lead, also known as the mineral crocoite (PbCrO4), in 1797. He produced chromium oxide (CrO3) by mixing crocoite with hydrochloric acid (HCl).
When was the chromium element discovered?
1797Chromium / Discovered
Who created chromium element?
chemist Nicolas-Louis VauquelinChromium was discovered (1797) by the French chemist Nicolas-Louis Vauquelin and isolated as the metal a year later; it was named for its multicoloured compounds.
Where is chromium discovered?
Chromium was discovered in 1780 by French chemist Nicolas Louis Vauquelin in Paris. He discovered the element in a mineral sample of 'Siberian red lead'- now known as crocoite (lead chromate).
Why is it called chromium?
Origin of the name The name is derived from the Greek 'chroma', meaning colour.
What is special about chromium?
Chromium is a lustrous, brittle, hard metal. Its colour is silver-gray and it can be highly polished. It does not tarnish in air, when heated it borns and forms the green chromic oxide. Chromium is unstable in oxygen, it immediately produces a thin oxide layer that is impermeable to oxygen and protects the metal below.
Why is chromium so colorful?
Discovered in 1797 by the French chemist Louis Nicolas Vauquelin, it was named chromium (Greek chroma, "colour") because of the many different colours characteristic of its compounds.
Where is chromium used?
New alloys – are formed using chromium. You might have seen chromium on the outside, but it is also mixed with metals to form alloys. Stainless steel and aluminium alloys use a small amount of chromium. Paints and Dyes – This useful element is also found in paint and dyes and chemical makeup that is used for fabrics.
How much chromium is in the earth?
Origin and Nature. Chromium is the seventh most abundant element on earth, most chromium residing in the core and mantle. In the earth's crust chromium ranks 21st, the average concentration being estimated to be 185 mg kg−1, much lower than that for the earth as a whole, estimated to be 3700 mg kg−1.
What are 5 uses of chromium?
It is mainly used in electroplating, tanning, printing, and dyeing, medicine, fuel, catalysts, oxidants, matches, and metal corrosion inhibitors. At the same time, metallic chromium has become one of the most important electroplated metals.
How is chromium produced?
Chromium metal is commercially produced in the United States by the reduction of chromite ore with carbon, aluminum, or silicon, and subsequent purification. Sodium chromate and dichromate are produced by roasting chromite ore with soda ash.
Is chromium the hardest metal?
With a rating of 8.5 on the Moh's hardness scale, chromium is the hardest metal on the planet (easily outclassing titanium, which is rated at a mere 6. Only boron and diamond sit above chromium on this scale, with ratings of 9.5 and 10 respectively.
Is chromium a rare earth metal?
chromium, which are found in abundance in the earth's crust, are also considered to be rare metals. This is because manganese and chromium have been essential elements for the industrial world since its early days, used as additives to enhance the properties of iron.
When was ruthenium discovered as an element?
1844Ruthenium was discovered by Karl Karlovich Klaus, a Russian chemist, in 1844 while analyzing the residue of a sample of platinum ore obtained from the Ural mountains.
Is chromium toxic to humans?
Human studies have clearly established that inhaled chromium (VI) is a human carcinogen, resulting in an increased risk of lung cancer. Animal studies have shown chromium (VI) to cause lung tumors via inhalation exposure.
Who discovered the color of chromium?
Chromium was discovered (1797) by the French chemist Nicolas-Louis Vauquelin and isolated as the metal a year later; it was named for its multicoloured compounds. The green colour of emerald, serpentine, and chrome mica and the red colour of ruby are due to small amounts of chromium.
Where is chromium found?
Asian countries with reserves of chromium include Turkey, the Philippines, India, Iran, and Pakistan; reserves are also found in northwestern Kazakhstan. Manganese is found in abundance, with large reserves in Transcaucasia, Central Asia, Siberia, and India; Chinese reserves also are considerable.
What is the name of the metal that is reduced with carbon?
The dichromate is then reduced with carbon to chromium sesquioxide, Cr 2 O 3, and that oxide in turn is reduced with aluminum to give the chromium metal. Chromium is added to iron and nickel in the form of ferrochromium to produce alloys specially characterized by their high resistance to corrosion and oxidation.
How to get chromium?
To obtain pure chromium, chromite is first treated with molten alkali and oxygen, converting all of the chromium to the alkali chromate, and the latter is dissolved in water and eventually precipitated as sodium dichromate, Na 2 Cr 2 O 7. The dichromate is then reduced with carbon to chromium sesquioxide, Cr 2 O 3, and that oxide in turn is reduced with aluminum to give the chromium metal.
What is the name of the group 6 element?
Full Article. Chromium (Cr), chemical element of Group 6 (VIb) of the periodic table, a hard steel-gray metal that takes a high polish and is used in alloys to increase strength and corrosion resistance. Chromium was discovered (1797) by the French chemist Nicolas-Louis Vauquelin and isolated as the metal a year later;
How many elements are in the periodic table?
The periodic table is made up of 118 elements.
What are the oxidation states of chromium?
The most common oxidation states of chromium are +6, +3, and +2. A few stable compounds of the +5, +4, and +1 states, however, are known. In the +6 oxidation state, the most important species formed by chromium are the chromate, CrO 42−, and dichromate, Cr 2 O 72−, ions. These ions form the basis for a series of industrially important salts.
What is chromium used for?
Chromium is widely used in metallurgy, chemical, cast iron, refractory and high-end technology industries.
Who discovered the red lead in Siberian ore?
In 1766, the German scientist Johann Gottlob Lehmann analyzed a Siberian ore and determined that it contained lead, which was classified as Siberian red lead.
Is chromium a pigment?
Chromium was initially used as a pigment. At present, nearly all chromium is commercially extracted from chromite, also known as iron chromium oxide (FeCr2O4).
Who discovered the color of chromium?
Chromium was initially discovered in red crystalline mineral form, known Siberian red lead, by Johann Gottlob Lehmann (1766). Later, chromium was discovered as a novel, and isolated metal by Louis-Nicolas Vauquelin in 1797. The name chromium has been derived from Greek word, chroma, which means color. The name was given to this metal as it exists in diverse colors and was suggested by, Antoine Francois de Fourcroy (1755-1809) and René-Just Haüy (1743-1822). Chromium has a distinct shine and forms various compounds in different colors that include green, purple, black, yellow, and orange [1].
Where does the name Chromium come from?
The name chromium has been derived from Greek word, chroma, which means color. The name was given to this metal as it exists in diverse colors and was suggested by, Antoine Francois de Fourcroy (1755-1809) and René-Just Haüy (1743-1822).
How many isotopes of chromium are there?
Natural chromium has four isotopes: chromium-50, chromium-52, chromium-53, chromium-54. There are twenty-one other isotopes of chromium. Chromium-53 is the most abundant among all isotopes. Several isotopes of chromium are used for medical purposes.
What is the source of chromium?
Chromite is the principal source of chromium that is used in pigments, worldwide. Chromium is released in the environment by erosion of rocks that contain chromium. Volcanic activities also play important role in the distribution of chromium.
What is chromium plating used for?
Chromium plating is used for bikes and cars. Chromium has been widely used in the manufacturing of dyes, pigments and paints due to its unique and wide range of colors. Chromium oxides are used for dying glass and ceramics. It imparts natural green color and is also used by armed forces to paint their tanks and vehicles to imitate infrared ...
What are the dangers of chromium?
Large amounts of chromium compounds are being released into environment by various industries, tanneries (paints, dyes, leather manufacturing), and pose threat of contamination of soil and water.
What is the widest use of chromium?
The widest usage of chromium is in the making of metal alloys. Chromium can impart strength corrosion resistance and shine to various metals and is widely used in the manufacturing of steel.
Where is chromium found?
Because chromium compounds were used in dyes, paints, and leather tanning compounds, these compounds are often found in soil and groundwater at active and abandoned industrial sites , needing environmental cleanup and remediation. Primer paint containing hexavalent chromium is still widely used for aerospace and automobile refinishing applications.
How is chromium obtained?
Chromium (III) can be obtained by dissolving elemental chromium in acids like hydrochloric acid or sulfuric acid , but it can also be formed through the reduction of chromium (VI) by cytochrome c7. The Cr3+#N#ion has a similar radius (63 pm) to Al3+#N#(radius 50 pm), and they can replace each other in some compounds, such as in chrome alum and alum .
What is the maximum reflectance of chromium?
Chromium has a high specular reflection in comparison to other transition metals. In infrared, at 425 μm, chromium has a maximum reflectance of about 72%, reducing to a minimum of 62% at 750 μm before rising again to 90% at 4000 μm.
How toxic is chromium?
The acute oral toxicity for chromium (VI) ranges between 1.5 and 3.3 mg/kg. In the body, chromium (VI) is reduced by several mechanisms to chromium (III) already in the blood before it enters the cells. The chromium (III) is excreted from the body, whereas the chromate ion is transferred into the cell by a transport mechanism, by which also sulfate and phosphate ions enter the cell. The acute toxicity of chromium (VI) is due to its strong oxidant properties. After it reaches the blood stream, it damages the kidneys, the liver and blood cells through oxidation reactions. Hemolysis, renal, and liver failure result. Aggressive dialysis can be therapeutic.
How many radioisotopes are in chromium?
Naturally occurring chromium is composed of three stable isotopes; 52 Cr, 53 Cr and 54 Cr, with 52 Cr being the most abundant (83.789% natural abundance ). 19 radioisotopes have been characterized, with the most stable being 50 Cr with a half-life of (more than) 1.8 × 10 17 years, and 51 Cr with a half-life of 27.7 days. All of the remaining radioactive isotopes have half-lives that are less than 24 hours and the majority less than 1 minute. Chromium also has two metastable nuclear isomers.
What is the atomic number of Chromium?
Chromium is a chemical element with the symbol Cr and atomic number 24. It is the first element in group 6. It is a steely-grey, lustrous, hard, and brittle transition metal. Chromium is the main additive in stainless steel, to which it adds anti-corrosive properties.
Is chromium a trace element?
The biologically beneficial effects of chromium (III) are debated. Chromium is accepted by the U.S. National Institutes of Health as a trace element for its roles in the action of insulin, a hormone that mediates the metabolism and storage of carbohydrate, fat, and protein. The mechanism of its actions in the body, however, have not been defined, leaving in question the essentiality of chromium.
When was chromium discovered?
Chromium was discovered within the mineral Siberian red lead in 1797 by French chemist Louis-Nicolas Vauquelin. The mineral had been discovered two decades prior and took on a form and color that was unlike any other mineral. Vauquelin was convinced the uniqueness of this mineral was due to an undiscovered metal.
What group is chromium in?
The Element Chromium. The element chromium (Cr) can be found in group 6 on the periodic table. It is silvery, lustrous, and hard. Moreover, it is well known for creating colorful compounds and is often used to both protect and polish other metals through a process called electroplating. Find out more about this radiant transition metal down below!
Where can I buy chromium?
Chromium mineral supplements are available on Amazon and in many stores. However, for laboratory purposes, the element chromium is available in specialty shops, it is not expensive and costs about ten dollars per 100 grams.
Why do we use chromium and oxygen?
The reason for using these two substances is that they will steal the oxygen from the compound and leave behind pure chromium metal. This is a method very similar to what Vauquelin did to isolate the element for the first time about 200 years ago.
What is the cause of chromium pollution?
Most of the chromium pollution in the environment is the result of waste from human activities such as mining and leather tanning. When disposed of in landfills, toxic chromium seeps from the soil into the water. One industry that contributes a large amount of chromium pollution is the ferrochrome industry.
What is the name of the element that is used to make colors?
Chromium is named after the Greek word ‘chroma’ which translates to ‘color’ and references the element’s ability to compose colorful compounds. 75% of chromium produced today is used in alloys such as stainless steel to protect and shine base metals such as copper or zinc. Southern Africa and Zimbabwe supply 99% of the world’s chromite which is ...
How is chromium left on top of metal?
It is accomplished by passing an electric current between two electrodes immersed in an electrolyte bath with chromic acid. The result is a thin layer of chromium being left on top of either a metal or alloy substrate.
Who discovered chromium?
Dr. Doug Stewart. Chromium was discovered in 1780 by French chemist Nicolas Louis Vauquelin in Paris. He discovered the element in a mineral sample of ‘Siberian red lead’- now known as crocoite (lead chromate). He boiled the crushed mineral with potassium carbonate to produce lead carbonate and a yellow potassium salt solution of chromic acid.
Why is chromium called chromium?
Chromium was named from the Greek word ‘chroma’, meaning color because it forms a variety of colorful compounds.
How did Vauquelin isolate chromium?
Vauquelin then obtained the oxide by evaporation and finally isolated chromium by heating the oxide in a charcoal oven. (1), (2).
How many isotopes does chromium have?
Isotopes: Chromium has 21 isotopes whose half-lives are known, with mass numbers 42 to 63. Naturally occurring chromium is a mixture of four isotopes and they are found in the percentages shown: 50 Cr (4.3%), 52 Cr (83.8%), 53 Cr (9.5%) and 54 Cr (2.4%).
What is chromium used for?
Uses of Chromium. Chromium is used in stainless steel, and other alloys. Chromium plating, for example on cars and bicycles, produces a smooth, silver finish that is highly resistant to corrosion. The metal is also widely used as a catalyst.
Is chrome a hard metal?
Chromium is a silver, lustrous, very hard metal that can take a high mirror polish. It is also odorless, tasteless, and malleable.
Is chromium a free element?
Source: Chromium is not found as a free element in nature but is found in the form of ores . The main ore of chromium is chromite FeCr 2 O 4.
Where was chromium discovered?
Chromium was discovered by the French chemist Nicholas Louis Vauquelin at Paris in1798. He was intrigued by a bright red mineral that had been discovered in a Siberian gold mine in 1766 and was referred to as Siberian red lead. It is now known as crocoite and is a form of lead chromate. Vauquelin analysed it and confirmed that it was a lead mineral. Then he dissolved it in acid, precipitated the lead, filtered this off, and focused his attention on the remaining liquor from which he succeeded in isolating chromium. Intrigued by the range of colours that it could produce in solution, he named it chromium from the Greek word chroma meaning colour. He then discovered that the green colouration of emeralds was also due to chromium
Where is chromium found?
Natural abundance. Chromium is found mainly in chromite. This ore is found in many places including South Africa, India, Kazakhstan and Turkey. Chromium metal is usually produced by reducing chromite with carbon in an electric-arc furnace, or reducing chromium (III) oxide with aluminium or silicon.
How did Vauquelin isolate chromium?
First he mixed the crocoite solution with potassium carbonate to precipitate out the lead. Then he decomposed the lemon yellow chromate intermediate in acid, and finally removed the compounded oxygen by heating with carbon - leaving behind elemental chromium.
What is chromium plating used for?
Chromium plating can be used to give a polished mirror finish to steel. Chromium-plated car and lorry parts, such as bumpers, were once very common. It is also possible to chromium plate plastics, which are often used in bathroom fittings.
What is the use of chromium?
The image reflects the toxic nature of the metal and its ‘mirror shine’ when polished. Appearance. A hard, silvery metal with a blue tinge. Uses. Chromium is used to harden steel, to manufacture stainless steel (named as it won’t rust) and to produce several alloys.
Why is chrome called chrome?
The name for this new element was debated among his friends, who suggested "chrome" from the Greek word for colour because of the colouration of its compounds. Although he objected to this name at first because the metal itself had no characteristic colour, his friends' views won out.
What is the vertical column in the periodic table?
A vertical column in the periodic table. Members of a group typically have similar properties and electron configurations in their outer shell. A horizontal row in the periodic table. The atomic number of each element increases by one, reading from left to right.
Overview
History
Chromium minerals as pigments came to the attention of the west in the eighteenth century. On 26 July 1761, Johann Gottlob Lehmann found an orange-red mineral in the Beryozovskoye mines in the Ural Mountains which he named Siberian red lead. Though misidentified as a lead compound with selenium and iron components, the mineral was in fact crocoite with a formula of PbCrO4. In 1770, Peter Simon Pallas visited the same site as Lehmann and found a red lead mineral that wa…
Physical properties
Chromium is the fourth transition metal found on the periodic table, and has an electron configuration of [Ar] 3d 4s . It is also the first element in the periodic table whose ground-state electron configuration violates the Aufbau principle. This occurs again later in the periodic table with other elements and their electron configurations, such as copper, niobium, and molybdenum. This occurs because electrons in the same orbital repel each other due to their like charges. In t…
Chemistry and compounds
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.
Many Cr(0) complexes are known. Bis(benzene)chromium and chromium hexacarbonyl are highlights in organochromium chemistry.
Occurrence
Chromium is the 21st most abundant element in Earth's crust with an average concentration of 100 ppm. Chromium compounds are found in the environment from the erosion of chromium-containing rocks, and can be redistributed by volcanic eruptions. Typical background concentrations of chromium in environmental media are: atmosphere <10 ng/m ; soil <500 mg/kg; vegetation <0.5 mg/kg; freshwater <10 μg/L; seawater <1 μg/L; sediment <80 mg/kg. Chromium i…
Production
Approximately 28.8 million metric tons (Mt) of marketable chromite ore was produced in 2013, and converted into 7.5 Mt of ferrochromium. According to John F. Papp, writing for the USGS, "Ferrochromium is the leading end use of chromite ore, [and] stainless steel is the leading end use of ferrochromium."
The largest producers of chromium ore in 2013 have been South Africa (48%), Kazakhstan (13%)…
Applications
The creation of metal alloys account for 85% of the available chromium's usage. The remainder of chromium is used in the chemical, refractory, and foundry industries.
The strengthening effect of forming stable metal carbides at grain boundaries, and the strong increase in corrosion resistance made chromium an important alloying material for steel. High-speed tool steels contain between 3 and 5% chromium. Stainless steel, the primary corrosion-resi…
Biological role
The biologically beneficial effects of chromium(III) are debated. Chromium is accepted by the U.S. National Institutes of Health as a trace element for its roles in the action of insulin, a hormone that mediates the metabolism and storage of carbohydrate, fat, and protein. The mechanism of its actions in the body, however, have not been defined, leaving in question the essentiality of chromium.