Chlorine element-Discovery, properties and uses


Written by Adeel Abbas

Chlorine is a chemical element with the symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate between them. Chlorine is a yellow-green gas at room temperature. in periodic table chlorine is present as a halogen.

Halogens are elements that tend to form diatomic molecules in their elemental state, X2. Chlorine is the most abundant halogen in the Earths crust and makes up about three percent of the planets mass. It is found almost entirely as chloride ions, Cl- , bound into minerals and salts.

Discovery of Chlorine

Chlorine was discovered by Carl Wilhelm Scheele in 1774, who named it after the Greek word khloros, meaning greenish-yellow. Chlorine gas was first used as a weapon by the French in World War I. The discovery of chlorine relates to when Carl Wilhelm Scheele, a Swedish pharmacist, was working with pyrolusite and noticed a green gas escaping from it. He called the gas dephlogisticated muriatic acid because it was produced by heating hydrochloric acid (muriatic acid). Joseph Priestley, an English chemist, later isolated chlorine

Physical Properties of Chlorine Element

Here are some important physical properties of chlorine element.

        1. Appearance Chlorine gas has a pale yellow color and is also known as liquefied chlorine or chloride of lime, because it readily forms compounds with almost all other elements. It can turn into liquid at -34 degrees Celsius and solidifies to form white crystals at -101 degrees C. They are commonly used in swimming pools to kill bacteria so that the pool stays clean for longer periods of time without too much cleaning, but care must be taken since they are corrosive.

        2. Melting Point/Melting Range- 26 °C

        3. Boiling Point/Boiling Range-150 °C

        4. Density- 2 grams per cm-1 cubed

Chemical Properties of Chlorine Element

The chemical properties of chlorine are similarly versatile, as it combines with most elements to form compounds called chlorides. Inorganic chemist John Emsley writes in Natures Building Blocks that chlorine is one of the most reactive elements known.

As an oxidizing agent, it can be used to remove organic material from plant samples for further study under a microscope. In industry, chlorine is used as a bleaching agent and as an ingredient in the manufacture of plastics and solvents. It can also disinfect water by killing most living organisms in it, making it easier to drink safely.

        1. Oxidizing Agent          

Chlorine is a strong oxidizing agent that readily forms compounds with many elements

        2. Reducing Agent       

Chlorine readily forms compounds with hydrogen to form hydrochloric acid, which is commonly used to clean pools and manufacturing equipment because of its corrosiveness .

        3) Reaction with Air        

Chlorine reacts with oxygen in air to form chlorine dioxide, a toxic gas.

        4) Reaction with Water     

Chlorine readily combines with water to form an acid known as hydrochloric acid. Because chlorine is so corrosive and can kill living organisms in water, it makes it harder for other microorganisms to live in the water thus making it safer for humans to drink.

        5) Other Reactions                        

  Chlorine readily forms compounds with hydrogen to produce an explosive called hydrogen chloride or phosgene that was used during World War I as a chemical weapon.


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Uses of chlorine element

1: It is used as a disinfectant, bleach and water treatment chemical.

2: Chlorine gas was used in the trenches of World War I to kill enemy soldiers with its lethal toxic effect.

3: It is also used for bleaching of paper and wood pulp and as a feedstock for the manufacture of organic chemicals such as plastics and solvents.

4: It is present in household cleaning products like bleach, disinfectants etc.

5: Chlorine has wide applications in the textile industry for treating fabrics to enable dyeing, printing etc.

6: Chlorine forms important compounds like chloroform (CHCl3), chlorobenzene (C6H5Cl) etc which are further useful in the production of plastics and other organic chemicals.

7: As a chlorinating agent it is used for treating water to make it safe for drinking and cooking purposes.

8: It is also used in manufacturing process of polyvinyl chloride (PVC), trichloroethylene, Freon-11 etc which are further used in plastic manufacture.

9: Chlorine compounds were used in warfare agents such as mustard gas and phosgene gas or riot control agents like CS gas.

10: In algae treatment, chlorine is effective against diatoms and flagellates.

11: It is also used in swimming pools and spas to maintain sanitary conditions.

12: Chlorine is an important ingredient of many medicines.

13: It is also used as a food additive to kill bacteria and protect against food spoilage.

14: Finally, it has some agricultural applications in crop protection and soil amendment.

Safety measurements while working with Chlorine

1: Always wear safety goggles and keep your face away from the Chlorine gas.

2: Keep a wet sponge in hand while working with chlorine to reduce the burning sensation when chlorine touches your skin. If this doesnt help, wash it thoroughly and go see a doctor immediately (with full safety gear on).

3: As much as possible, dont work alone when handling chlorine. Also make sure you arent distracted or tired whenever working around it. 

4: Before starting any experiment using the element, think properly whether there is any other easier way to achieve what you want (and if yes-leave such experiments for later). Its not worth harming yourself just by doing some science project that could have been done conducting simple experiments.

5: When using chlorine as a bleach (such as water purification), use it in its concentrated form and dilute only after the experiment is done.

6: Its recommended that you consult safety experts before working around or near it. They would be more helpful than this article for your safety measures.

7: If you feel like there is any abnormal thing happening to your body (or anyone else nearby) immediately go see a doctor even if you are 100% sure its not related to working with Chlorine. Please dont keep thinking about what ifs and just go ASAP. Remember-time lost now might save time later on your life!

8: Always try to work with small quantities of chlorine at a time. And if you are using a gas form, make sure the area is well-ventilated.

9: Lastly and most importantly, have fun with chlorine but always be safe!

Disposal methods for Chlorine

1: Chlorine can be released into the environment through a number of industrial processes, including chemical production, metal smelting and water disinfection.

2: Chlorine is also released when organic materials, such as garbage or sewage, are incinerated.

3: Because chlorine is a gas, it can escape from poorly sealed containers or storage tanks and drift into the atmosphere.

4: Chlorine emissions can also enter waterways through wastewater discharge and runoff from landfills and agricultural areas.

5: Once in the environment, chlorine can persist for long periods of time and cause serious damage to ecosystems.

FAQs related to Chlorine element

1. What is chlorine?

Chlorine is a chemical element with the symbol Cl and atomic number 17. It is the second-lightest of the halogens, appearing between fluorine and bromine in the periodic table. Chlorine is a yellow-green gas at room temperature.

2. How chlorine was discovered?

Chlorine was first isolated around 1774 by Swedish chemist Carl Wilhelm Scheele, who called it dephlogisticated muriatic acid and mistakenly thought it contained oxygen (in fact, chlorine contains no oxygen). Although Scheeles name for chlorine (hypochlorite) remained in wide use until 1809 (when Antoine Lavoisier gave it the present name), other names were used too; notably dephlogisticated marine acid by Joseph Priestley in 1772.

3. What are some important uses chlorine?

Chlorine is mainly used as a disinfectant, bleach and water treatment chemical. It has also been used in the trenches of World War I to kill enemy soldiers with its lethal toxic effect. Chlorine is also used for bleaching of paper and wood pulp, as a feedstock for the manufacture of organic chemicals such as plastics and solvents, and in many medicines. Finally, it has some agricultural applications in crop protection and soil amendment.

4. Are there any dangers associated with chlorine?

Yes, chlorine can be dangerous if not handled properly. It can cause severe burns if it comes into contact with the skin and it can be toxic if inhaled. It is also a fire hazard.