Chromium

7.15
51.996
[Ar] 3d54s1
52Cr
6
4
d
24
2, 8, 13, 1
652.869
Cr
7.15
1907°C, 3465°F, 2180 K
2671°C, 4840°F, 2944 K
Nicholas Louis Vauquelin
1798
7440-47-3
22412
More Information
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Uses and Properties

Image Explanation

Chromium is used in the production of stainless steel and plays a significant role in hardening steel used for the production of Kitchen utensils.

Appearance

A hard, silvery metal with a blue tinge.

Uses



Chromium: Shining a Spotlight on a Versatile Element






Chromium, denoted by the atomic number 24 and the symbol Cr on the periodic table, is a metal with a remarkable array of applications. From its role in the world of stainless steel to its contributions in the fields of industry, technology, and health, chromium has firmly established itself as a versatile and indispensable element. In this article, we'll delve into the diverse uses of chromium and how it influences our daily lives.

 

1. Stainless Steel Production


One of the most well-known uses of chromium is in the production of stainless steel. Stainless steel is a popular choice in various industries, including construction, architecture, kitchenware, and medical equipment, thanks to its exceptional corrosion resistance, durability, and attractive appearance.

The addition of chromium to steel, typically in the range of 10-30%, forms a passive oxide layer on the surface of the material. This oxide layer is what gives stainless steel its "stainless" characteristics, preventing rust and staining when exposed to moisture and corrosive environments. Whether it's a kitchen knife, a modern building's facade, or a medical instrument, chromium's role in stainless steel is unmistakable.

 

2. Aerospace and Aircraft Components


Chromium's exceptional heat resistance and strength make it a valuable element in the aerospace industry. Chromium-based alloys are used to create critical components of aircraft, such as jet engines and gas turbines. The high-temperature environment in these applications demands materials that can withstand extreme conditions. Chromium's ability to maintain its structural integrity under high temperatures contributes to the safety and efficiency of air travel.

 

3. Corrosion-Resistant Coatings


Beyond stainless steel, chromium finds its way into various coatings and platings. Chrome plating, also known as chromium plating, involves electroplating a thin layer of chromium onto the surface of an object. This process provides the object with enhanced corrosion resistance, an attractive finish, and improved wear resistance.

Chrome plating is used in applications such as automotive trim, plumbing fixtures, and even decorative items. Its lustrous appearance, along with its protective qualities, makes chrome-plated objects stand out in terms of both aesthetics and functionality.

 

4. Diverse Applications in the Chemical Industry


Chromium compounds are widely used in the chemical industry for a variety of purposes. For example, sodium dichromate and potassium dichromate are used in laboratory settings as oxidizing agents, while chromic acid is employed for cleaning glassware and etching materials. In addition, chromium catalysts are vital in various chemical processes, such as the production of synthetic rubbers, plastics, and dyes.

 

5. Hardening Steel


Chromium is an essential alloying element when it comes to hardening steel. When combined with steel in specific quantities, it forms hard and wear-resistant carbides within the steel's structure. This process, known as "chromium hardening," increases the steel's hardness and wear resistance. The resulting hardened steel is commonly used to produce tools, bearings, gears, and various mechanical components that require durability and strength.

 

6. Decorative and Reflective Finishes


Chromium is admired for its mirror-like finish and ability to reflect light. This makes it a popular choice in applications where aesthetics and reflectivity are paramount. It is commonly used for decorative finishes on items such as automotive bumpers, light fixtures, and even jewelry. Chromium's ability to create a bright and reflective surface adds a touch of sophistication to a wide range of products.

 

7. Leather Tanning


Chromium plays a crucial role in the leather industry. Chromium tanning is a widely adopted method for processing animal hides into leather. The process involves treating the hides with chromium salts, resulting in a soft, durable, and water-resistant leather that is used in the production of shoes, bags, upholstery, and various other leather products.

 

8. Health and Dietary Supplements


Chromium has gained recognition in the field of health and nutrition. It is an essential trace element required by the human body in small quantities. Chromium is believed to play a role in regulating blood sugar levels and is often used in dietary supplements designed to support glucose metabolism.

 

9. Environmental Remediation


Chromium's presence in environmental cleanup is notable. Hexavalent chromium, a toxic form of the element, has been a focus of attention due to its environmental impact. Efforts to remediate contaminated sites and manage the impact of chromium pollution have led to the development of innovative techniques and technologies.

 

Conclusion


Chromium's diverse uses span multiple industries and touch various aspects of our lives. From the gleaming finishes of our automobiles to the durable tools we use, and even to the regulation of blood sugar, chromium is a versatile element that quietly influences our world. Its unique properties make it an indispensable component in numerous applications, contributing to advancements in technology, safety, and quality of life. As we look to the future, it's clear that chromium will continue to shine brightly in various sectors, both old and new, making our lives better and more efficient.

History

Chromium, with its striking silver luster and diverse applications, has a rich and intriguing history. From its discovery to its pivotal role in modern technology and industry, this remarkable element has undergone a journey that spans centuries. In this article, we delve into the captivating history of Chromium, from its early days as a mysterious mineral to its widespread presence in our daily lives.

 

Discovery and Early Encounters


The story of Chromium begins with its identification and isolation. In the late 18th century, it was often confused with other elements, primarily iron, lead, and silver. It wasn't until the early 19th century that progress was made in distinguishing Chromium as a distinct element.

In 1797, French chemist Nicolas-Louis Vauquelin isolated Chromium oxide from Siberian red lead ore. This marked the initial step towards recognizing Chromium as a unique element. He later succeeded in producing metallic Chromium by reducing Chromium oxide with aluminum.

The name "Chromium" derives from the Greek word "chroma," meaning color, aptly chosen due to the vibrant and colorful compounds formed by this element. The ability of Chromium to create an array of pigments became one of its early claims to fame.

 

Chromium's Role in Pigments


During the 19th century, Chromium found a special place in the realm of art and coloration. Chrome yellow, a popular pigment, was created using lead chromate. This vivid and durable pigment became a favorite choice among artists and manufacturers. It provided a brilliant yellow hue to everything from paintings to ceramics.

As the understanding of Chromium's properties grew, it was clear that its ability to produce vibrant colors extended beyond yellow. The green pigment, chrome green, was also developed using Chromium compounds, expanding the artistic palette and finding applications in the world of ceramics and textiles.

 

Chromium's Contribution to Metallurgy


Chromium was not confined to the world of art; its entry into the world of metallurgy was equally significant. Its unique properties, including resistance to corrosion and strength, made it an appealing element in the production of steel. Chromium, when alloyed with steel, enhances its durability and resistance to oxidation.

The use of Chromium in stainless steel, which has become a hallmark of modern industry, was instrumental in the creation of materials that could withstand harsh environments. From cutlery and kitchen appliances to architectural structures, the influence of Chromium in stainless steel is far-reaching.

 

Chromium in the Aerospace Industry


In the 20th century, Chromium's journey extended to the aerospace industry. Its remarkable heat resistance and strength made it a prized element in the construction of aircraft engines and gas turbines. The ability to withstand high temperatures, a necessity in these applications, contributed to the safety and efficiency of air travel.

 

Chromium's Journey into Modern Technology


As the world transitioned into the digital age, Chromium's role expanded into the realm of modern technology. Chromium's remarkable reflective properties and corrosion resistance made it an ideal material for use in products such as automotive bumpers and light fixtures. Its mirror-like finish added a touch of sophistication to these objects.

In the field of electronics, Chromium played a vital role in the development of the first-generation computer magnetic tapes. These tapes were coated with a layer of Chromium, enhancing their performance and reliability in data storage.

 

Chromium in Health and Nutrition


Chromium's significance is not limited to the world of industry and technology. It has made its way into the realm of health and nutrition. Chromium is considered an essential trace element, meaning the human body requires it in small quantities for normal functioning. It plays a role in glucose metabolism and insulin regulation. As a result, Chromium supplements have gained recognition in dietary support for individuals looking to manage their blood sugar levels.

 

Chromium's Environmental Impact


While Chromium has found widespread utility, it has not been without controversy. The hexavalent form of Chromium, often associated with pollution and environmental concerns, gained notoriety due to its toxic nature. The environmental impact of hexavalent Chromium has led to strict regulations and research aimed at mitigating its effects.

Chromium's history is a testament to human curiosity, innovation, and the adaptability of the elements. From its early discovery in Siberia to its role in art, industry, technology, and health, Chromium has proven to be a versatile and invaluable element. Its ability to create brilliant pigments, enhance steel's strength, and contribute to advancements in aerospace and technology showcases its diversity.

As we continue to explore new frontiers in science, technology, and industry, it's evident that Chromium's journey is far from over. This versatile element will undoubtedly continue to shine brightly in various sectors, contributing to the progress and quality of life for generations to come.

Atomic Data

Atomic Radiues, Non-bonded (A): 2.06
Electron Affinity (kJ mol-1): 64.259
Covalent Radiues (A): 1.30
Electronegativity (Pauling Scale): 1.66
Ionisation Energies (kJ mol-1) 1st 2nd 3rd 4th 5th 6th 7th 8th
652.869 1590.628 2987.19 4743.22 6701.87 8744.939 15455.02 17820.8

Oxidation States and Isotopes

Common oxidation states 6, 3, 2, 0
Isotope Atomic Mass Natural Abundance Half Life Mode of Decay
50Cr 49.946 4.345 > 1.3 x 1018 y β+EC
52Cr 51.941 83.789 - -
53Cr 52.941 9.501 - -
54Cr 53.939 2.365 - -

Supply Risk

Relative Supply Risk: 6.2
Crustal Abundance (ppm): 135
Recycle Rate (%): >30
Production Conc.(%) : 37
Top 3 Producers:
1) South Africa
2) Kazakhstan
3) India
Top 3 Reserve Holders:
1) Kazakhstan
2) South Africa
3) India
Substitutability: High
Political Stability of Top Producer: 44.3
Political Stability of Top Reserve Holder: 61.8

Pressure and Temperature Data

Specific Heat Capacity: 449
Shear Modulus: 115.4
Young Modulus: 279.1
Bulk Modulus: 160.1
Pressure 400k Pressure 600k Pressure 800k Pressure 1000k Pressure 1200k Pressure 1400k Pressure 1600k Pressure 1800k Pressure 2000k Pressure 2200k Pressure 2400k
- - - 2.45 x 10-8 7.59 x 10-5 0.0239 1.8 52.1 774 - 160.1

Podcast

Transcript :



Chrome has an atomic number of 24. On the scientific structure, it may be found in 6th grouping. The valence shell of chromium contains 6 electrons. The most important species that are generated by chromium in the +6 oxidation state are dichromate ions. Despite its low concentrations in the air and water, Chromium can cause health problems. It can affect the ability of an organism to fight off disease. For example, it is associated with lung cancer. Other effects include infertility and birth defects.

Though chromium may be found in many different meals, this element is most concentrated in greens. It also has the ability to alter cell signaling. Modifications to gene output are a direct consequence of the heightened signaling. These alterations are known to promote tumor growth. Chromite is composed of iron II oxide and chromium III oxides. This active ingredient is a potent oxidant. Chromium is not affected by water at normal temperatures. This element is also a very polishable metal. Several different compounds are manufactured from chromium. They range in colour from yellow to purple, green and black. Many of these substances have a high potential for toxicity.

The history of chromium is long and varied. It was discovered by French chemist Louis-Nicholas Vauquelin. Through a series of chemical reactions involving charcoal and chromium trioxide, he was able to synthesize a crystalline form of the metal. It was in a sample of a mineral that he obtained from the Ural Mountains that he made the discovery. When he boiled the mineral with potassium carbonate, he produced a yellow solution of chromic acid. This convinced him that the mineral was indeed a new element.

He named it chromium, after the Greek word for color. At the time, Vauquelin was studying crocoite, a mineral.

Vauquelin separated the metals from the occurrences by heating the mixture in an oven with charcoal. After heating it, he found the chromium oxide and the chromium metal.

In the 1920s, a process for producing chromium was developed. The Chemical Treatment Company of New York advertised a chromium plating service in the mid-1920s.

The metal chromium ranks as the planet's 7th most prevalent substance. It occurs in a variety of forms, and its presence in our environment is influenced by human activity Chromium is also found in chromite, a mineral. To put it simply, it does not occur naturally for free. Nonetheless, chromium exists in the environment in trace concentrations.

Chromite is mined in Finland, Russia, New Zealand, Australia, Turkey, and the Philippines. Among its many activities, it is found in resistive heating components and the metals-making process.

Trivalent chromium is naturally occurring in the environment and in rocks as well as can be found in the form of chromium trioxide, a green oxide. This type of chromium is mainly absorbed by plants.

Chromium is found in ores and soils. This element occurrence and production in nature is determined by geochemical controls.

It is commonly found in a variety of foods, including meat, cheese, poultry, fruits, vegetables and grains. It also exists in the soil and air. Because of its ability to attach to soil particles, chromium is released into the air and water.

Chromium has unique properties. These properties include high hardness and resistance to tarnishing. These properties are often combined in applications to provide increased strength. The oxidation state of chromium also affects its properties. When an atom is oxidized, it undergoes a redox reaction that produces an oxide. Its oxidation state varies from Cr III to Cr VI. Both forms are important to living organisms. However, chromium VI is highly toxic. In addition, it can interfere with genetic material.

In the +6 oxidation state, chromium generates chromate ions, which are the most significant species produced. Chromium combines with sulfur to produce sulfide compounds. Another chemical process involves the direct reaction of chromium with hydrogen sulfide to create chromium sulfate. When a chromium atom is heated, it forms a green chromic oxide. This chromic oxide can be made into a metallic form by reacting with aluminum. These properties make chromium a good choice for surfacing.

Chromium is known to be a corrosion-resistant material, odorless and tasteless nature, the crystalline form of chromium is silvery and grey in color. This element is also magnetic. It is a highly toxic metal, Chromium is a metal that has a density of 7.15 grams per cubic centimeter. This makes it very malleable. The melting point of chromium is 1907ºC. Chromium is a hard, silvery white or gray metal. Among its important properties, this element is a good conductor of electricity. Unlike many other elements, Chromium is not tarnished in air. When chromium reacts with halogens, it produces chromate ions.

Chromium's colors have fascinated people since ancient times. The Qin Dynasty in China, for example, used chromium oxide to coat weapons. The metal is used in many alloys, and it's a great addition to steel to increase corrosion resistance. In the early 1800s, chromium was used to produce a bright silver mirror coating for metals. . Sodium dichromate is used as an oxidizing agent in organic chemistry. A number of industries have benefited from the use of chromium-based surface treatments. These include chromium plating, zinc passivation, and black chromium plating. Some of these processes are now being improved by new proprietary chemistry.

One of the most commonly used applications is stainless steel. Where it adds strength and corrosion resistance .Stainless steel has many different uses, including in appliances, automotive, and electronics. Some applications require corrosion-resistant coatings.

Another application of chromium is in super alloys. These materials contain a higher percentage of chromium than stainless steel, and are used in a variety of end uses. These include aerospace, chemical, and automotive.

In the 1800s, chromium was used as a component of paints. However, the use of chromium-based paints became less common because of their toxic effects. A replacement was developed in the form of organic paints.

Chromium was also used as a tanning agent. It's a key ingredient of beryl, the raw material from which emerald is fashioned. Further, synthesized rubies are made out of chromium alloys. In industry, chromium is used almost exclusively in metal alloys.

References


  • W. M. Haynes, ed., CRC Handbook of Chemistry and Physics, CRC Press/Taylor and Francis, Boca Raton, FL, 95th Edition, Internet Version 2015, accessed December 2014.

  • Tables of Physical & Chemical Constants, Kaye & Laby Online, 16th edition, 1995. Version 1.0 (2005), accessed December 2014.

  • J. S. Coursey, D. J. Schwab, J. J. Tsai, and R. A. Dragoset, Atomic Weights and Isotopic Compositions (version 4.1), 2015, National Institute of Standards and Technology, Gaithersburg, MD, accessed November 2016.

  • T. L. Cottrell, The Strengths of Chemical Bonds, Butterworth, London, 1954.

  • John Emsley, Nature’s Building Blocks: An A-Z Guide to the Elements, Oxford University Press, New York, 2nd Edition, 2011.

  • Thomas Jefferson National Accelerator Facility - Office of Science Education, It’s Elemental - The Periodic Table of Elements, accessed December 2014.