[Ne] 3s23p5
35Cl, 37Cl
2, 8, 7
−101.5°C, −150.7°F, 171.7 K
−34.04°C, −29.27°F, 239.11 K
Carl Wilhelm Scheele
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Uses and Properties

Image Explanation

Sodium chloride is often referred to as table salt, common salt, or just simply salt.


A yellowy-green dense gas with a choking smell.


Chlorine: The Versatile Element Transforming Our Lives

Chlorine, symbolized as Cl on the periodic table, is a chemical element known for its distinctive properties and numerous applications. It has played a transformative role in various industries and sectors, from public health to water treatment, and it continues to be an essential component in countless products and processes. In this article, we will explore the diverse and vital uses of chlorine, highlighting its contributions to sanitation, industry, medicine, and more.


1. Water Disinfection: Safeguarding Public Health

One of chlorine's most significant contributions to society is in water disinfection. Chlorine is used to treat drinking water, swimming pool water, and wastewater to eliminate harmful microorganisms and pathogens. The process, known as chlorination, has had a profound impact on public health by reducing the spread of waterborne diseases, such as cholera and typhoid.


2. Bleaching and Sanitization: Brightening Fabrics and Surfaces

Chlorine-based bleaches and sanitizers are widely used in households and industries for various cleaning and disinfection purposes. Chlorine bleach is effective at removing stains and whitening fabrics, making it a staple in laundry rooms. In industrial settings, chlorine-based sanitizers play a vital role in food processing, hospital sterilization, and surface disinfection.


3. PVC Production: Building Blocks of Modern Life

Polyvinyl chloride (PVC) is a versatile and widely used plastic polymer. Chlorine is a key component in the production of PVC, contributing to its durability, flexibility, and resistance to chemical and weather-related damage. PVC is used in a multitude of applications, including pipes, cable insulation, clothing, and medical devices.


4. Pharmaceuticals and Medical Disinfection: Preserving Health

Chlorine-based compounds are essential in the pharmaceutical and medical industries. Chlorine dioxide, for example, is used to disinfect medical equipment and sterilize surfaces in healthcare facilities. Chlorine's role in pharmaceuticals extends to the production of medications and antiseptics.


5. Paper Production: Pulp Bleaching

Chlorine compounds have historically played a significant role in the paper and pulp industry. Chlorine dioxide is used to bleach wood pulp, helping to produce high-quality paper products. Although there has been a shift toward more environmentally friendly bleaching processes, chlorine still remains a part of the papermaking process.


6. Swimming Pool Disinfection: Safe Recreational Water

Chlorine is a primary disinfectant for swimming pools. It effectively kills bacteria and prevents the growth of harmful microorganisms in pool water, ensuring the safety of swimmers. The use of chlorine in pools is essential for maintaining water quality and preventing waterborne diseases.


7. Chemical Synthesis: A Versatile Building Block

Chlorine is a fundamental element in the chemical industry. It serves as a versatile building block for the synthesis of various compounds, including solvents, refrigerants, and plastics. Chlorine compounds also play a crucial role in the manufacture of dyes, pharmaceuticals, and agrochemicals.


8. Disinfection in Food Processing: Ensuring Food Safety

Chlorine-based disinfectants are used in food processing to reduce the risk of contamination and foodborne illnesses. They help sanitize equipment, surfaces, and water used in food production. Chlorine's role in food safety is essential in maintaining the quality and integrity of the food supply.


9. Soil Fumigation: Enhancing Crop Yield

Chlorine compounds are employed in soil fumigation to control pests and pathogens that can harm crops. Fumigation helps improve soil quality and crop yield by reducing the impact of diseases and pests. It is a valuable practice in agriculture for the protection of important crops.


10. Metal Extraction: Refining Processes

In metallurgy, chlorine is used in refining processes to extract metals such as titanium and zirconium. Chlorination is an effective method for removing impurities from ores and ensuring the quality of metals used in various industries, from aerospace to construction.


Chlorine's Enduring Impact

Chlorine, with its numerous and diverse applications, has become an integral part of modern life. From ensuring safe drinking water to enhancing food safety and enabling the production of essential materials and products, chlorine's versatility and effectiveness have transformed industries and safeguarded public health. Its enduring impact on sanitation, industry, and technology is a testament to the significance of this remarkable element. Chlorine continues to play a vital role in shaping our world and ensuring the well-being of our communities.


Chlorine, symbolized as Cl on the periodic table, is a chemical element with a history as fascinating as its uses are diverse. From its discovery and early experiments with alchemy to its pivotal role in modern public health, chlorine's journey through time is a testament to human curiosity and innovation. In this article, we will embark on a historical odyssey to explore the captivating evolution of chlorine, from an enigmatic substance to a life-saving public health tool.


Ancient Alchemy: Early Encounters with Chlorine

Chlorine's history can be traced back to ancient civilizations, where it often remained shrouded in mystery. Known for its distinctive greenish-yellow color and pungent odor, chlorine was often encountered in its natural state as the mineral halite, also known as rock salt.


Discovering the Green Gas: Scheele and Berthollet

The element chlorine was first isolated and identified in the late 18th century. Swedish chemist Carl Wilhelm Scheele is credited with discovering chlorine gas in 1774, although he initially believed it to be a compound rather than an element. French chemist Claude Louis Berthollet independently isolated chlorine gas in 1785 and recognized its elemental nature.


The Bleaching Power of Chlorine: Early Industrial Use

One of the earliest industrial applications of chlorine was its use as a bleaching agent for textiles and paper. The process, known as "chlorine bleaching," became increasingly important in the textile and paper industries during the 18th and 19th centuries. Chlorine's effectiveness at breaking down pigments and removing stains revolutionized the production of white textiles and high-quality paper products.


Chlorine in Water Disinfection: A Public Health Breakthrough

One of the most significant turning points in chlorine's history was its introduction to water disinfection. In the early 20th century, the link between waterborne diseases and contaminated drinking water became increasingly evident. The use of chlorine to disinfect water emerged as a game-changer in public health.


Chlorination of Drinking Water: A Milestone for Sanitation

The first large-scale application of chlorine for water disinfection occurred in the United States in 1908 in Jersey City, New Jersey. This marked a significant milestone in public health, as it significantly reduced the incidence of waterborne diseases like cholera and typhoid fever. Chlorine's ability to kill harmful microorganisms in water made it a powerful tool in ensuring safe drinking water for communities.


World War I and Chemical Warfare: A Dark Chapter

Chlorine had a less noble role during World War I when it was used as a chemical weapon. The devastating effects of chlorine gas on soldiers in the trenches highlighted the dangers of chemical warfare and led to international agreements aimed at restricting its use.


Modern Chlorine Applications: Beyond Disinfection

Chlorine's role in public health expanded with the development of chlorine-based disinfectants for hospitals, food processing, and swimming pool water. Chlorine compounds, such as sodium hypochlorite (bleach), became household staples for sanitation and cleaning.


The Environmental Impact and Alternatives

While chlorine has played a crucial role in disinfection and sanitation, concerns have arisen regarding its environmental impact. Chlorine compounds can react with organic matter in water to form disinfection byproducts (DBPs), some of which are potentially harmful. This has led to the exploration of alternative water treatment methods and disinfection technologies, such as ozone and ultraviolet (UV) treatment.


Chlorine's Enduring Legacy

Chlorine's journey from alchemical curiosity to public health champion is a testament to human ingenuity and adaptability. Its pivotal role in water disinfection and sanitation has saved countless lives, ensuring access to safe drinking water for millions. Despite challenges and evolving environmental concerns, chlorine remains a vital element in maintaining public health and hygiene. Its enduring legacy continues to shape the way we approach water treatment and sanitation, emphasizing the crucial balance between its benefits and potential environmental impacts. Chlorine's journey through history is a remarkable example of science and innovation making a profound impact on society.

Atomic Data

Atomic Radiues, Non-bonded (A): 1.75
Electron Affinity (kJ mol-1): 348.575
Covalent Radiues (A): 1.00
Electronegativity (Pauling Scale): 3.16
Ionisation Energies (kJ mol-1) 1st 2nd 3rd 4th 5th 6th 7th 8th
1251.186 2297.663 3821.78 5158.608 6541.7 9361.97 11018.221 33603.91

Oxidation States and Isotopes

Common oxidation states 7, 5, 3, 1, -1
Isotope Atomic Mass Natural Abundance Half Life Mode of Decay
35Cl 34.969 75.76 - -
36Cl 36.966 24.24 - -

Supply Risk

Relative Supply Risk: 4
Crustal Abundance (ppm): 145
Recycle Rate (%): Unknown
Production Conc.(%) : 24.3
Top 3 Producers:
1) China
2) India
3) USA
Top 3 Reserve Holders:
Substitutability: Unknown
Political Stability of Top Producer: 24.1
Political Stability of Top Reserve Holder: Unknown

Pressure and Temperature Data

Specific Heat Capacity: 479
Shear Modulus: Unknown
Young Modulus: Unknown
Bulk Modulus: 1.1 (liquid)
Pressure 400k Pressure 600k Pressure 800k Pressure 1000k Pressure 1200k Pressure 1400k Pressure 1600k Pressure 1800k Pressure 2000k Pressure 2200k Pressure 2400k
- - - - - - - - - - 1.1 (liquid)


Transcript :

Chlorine is the second lightest halogen on the planet. It is a highly electronegative element. The atomic structure of Chlorine has 17 protons and 17 electrons. The first and second electron shells have two and eight electrons, respectively. It has seven valence electrons. This outermost electron shell tends to form an anion. However, it can also be stable enough to form a molecule. There is a correlation between the amount of time spent in Chlorine and the severity of the consequences. At low levels, it can cause coughing, water retention in the lungs, and throat irritation. At higher levels, it can cause vomiting and chest pain. It can also contribute to oxidative damage in microorganisms. It's also used as a vital component in several medications. There are several chemical compounds that include it as well. It's a key ingredient in many different types of chemical manufacturing, including antiseptics and colors.

In reality, this substance has been crucial to human survival for millennia. Biologically, Chlorine has been important for thousands of years. Plants die or become sick when they receive too little Chlorine from the soil.

Some of the more harmful and persistent chemicals that contain Chlorine are referred to as dioxins. These toxic compounds are byproducts of industrial processes that involve Chlorine.

Chlorine was discovered by a Swedish chemist. During the 19th century, chemists began to understand the properties of Chlorine. In 1810, Sir Humphry Davy confirmed that Scheele had actually found a pure element. He named it khloros, which means pale green in Greek. He also called it dephlogisticated marine acid, later known as Chlorine.

The discovery of Chlorine was followed by the creation of several different Chlorine -containing chemicals. They were utilized by early alchemists to create a wide range of chemicals. Some of the most common were halite, camallite, pyrolusite, and potassium magnesium chloride hexahydrate.

The history of Chlorine has been quite eventful and after its discovery, chloride became an important part of life. A number of different chemicals have been made from it. The most famous is dichlorodiphenyltrichloroethane, also known as DDT. This was not widely used as a pesticide until the Second World War. It was later banned in the US and Europe.

The occurrence and production of Chlorine began with the discovery of the element by Carl Wilhelm Scheele in 1774. At the time, he thought that he had found a compound that contained oxygen. Later, he realized that he had discovered Chlorine. This element is found in massive concentrations on Earth. In nature, Chlorine is found in a number of minerals and seawater. When it is combined with other elements, it forms compounds such as chlorides. There are estimated to be 1016 tons of Chlorine in the ocean.

Having the right knowledge of the properties of Chlorine is very important. It is a diatomic gas. It is a halogen with a high electron affinity and is a chief oxidizer. This element has a pK a, value of 17 and its electronegativity is 3.16 on the Pauling scale. The atoms of Chlorine easily replace the hydrogen atoms in organic molecules. Its physical and chemical characteristics are transitional among those of fluoride and bromide. There are several oxidation states of Chlorine. Its reactivity is higher than that of fluorine. It can react with most elements except noble gases. In addition, it has a high ionization energy.

Chlorine has a relatively low melting point. At room temperature, it has a pale yellow-green color. Its density is 2.5 times than air, and has a latent heat of vaporization of 10.2 kJ/mol.

Throughout the twentieth century, Chlorine played a central role in chemical warfare. It was used in the First World War as a suffocating agent, and hundreds of cylinders were released by the German army in 1915.

The first use of Chlorine to treat public water supplies was in Great Britain around the turn of the century. It was found to be effective at Croydon typhoid outbreak of 1937. This element was also used to disinfect water in the pulp and paper industry.

Chlorine is used to create a vast array of items. For instance, it is also used in manufacturing polymers, silicones, and bumpers. This element is also used to sterilize drinking water. Chlorine is also used as an oxidizing agent in organic chemistry. These compounds are used to produce a wide variety of products, including paints, refrigerants, and insecticides.

In the mid-1800s, chemists discovered that chlorination could be applied to the disinfection of public water supplies. This process made the water safer and healthier to drink.

It has been associated with respiratory disease and is linked to certain protozoans.

Another practical use of Chlorine was bleaching. After a typhoid outbreak in England, a solution of bleach was added to the water. This resulted in a drastic drop in typhoid fever.

It is also a component of several common products. Moreover, pharmaceutical companies use Chlorine in the production of drugs.

It can replace hydrogen in synthetic rubbers and can be used to denature essential chemicals. This can be beneficial in several industries.

Plants rely on them because they produce Chlorine, which is necessary for their survival


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