Chlorine is one of the several chemical elements which are essential for various lifeforms, including humans. Its use by humans can be traced back to the ancient times wherein sodium chloride, which happens to be the most common compound of chlorine, was used in form of rock salt and brine. If chlorine is considered one of the most important chemical elements on Earth today, it is largely because of its uses.
Chlorine Properties in Brief: Chlorine is a member of the halogen family of elements, which also has iodine, bromine, and fluorine to its credit. The atomic number of chlorine is 17 and its symbol is 'Cl'. It has an atomic mass of 35.453 g.mol-1 and a density of 3.2 g/L. It is yellowish green in color and has a pungent odor, which makes it smell like bleach. Chlorine has a melting point of -150.7 °F and boiling point of -29.27 °F. Even though it is found in a gaseous state at room temperature, it has to be pressurized and cooled if it needs to be stored or transported.
Uses of Chlorine
Chlorine is used as a disinfectant in water treatment plants all over the world primarily because of its low cost and effectiveness. Basically, it gets rid of pathogens in the water and helps keep waterborne disease outbreaks at bay. The process wherein chlorine is used for the purpose of water purification is referred to as water chlorination. Other than water treatment plants, this chemical element is also widely used in sewage and wastewater treatment plants.
If you are into swimming, you must have noticed that the swimming pool water is usually chlorinated. When added to the pool water, chlorine breaks down into hypochlorous acid and other such chemicals, which kill the bacteria that are harmful for human health. As a disinfectant, it is also used to kill bacteria which accumulate in water puddles, air conditioning systems, etc.
As for the field of medicine, approximately 85 percent of medicines either contain chlorine or are manufactured using it. Some compounds of chlorine are also used in antiseptics as they prevent bacterial growth in wounds and burns. Chlorine compounds are widely used as cleaning and disinfecting agents in medical facilities all over the world, especially for disinfecting the machines and equipment used in these facilities.
Though it doesn't catch fire easily, chlorine can be used with some other substances to form explosive compounds. In fact, it has even been used as a chemical warfare agent in the past. Classified as a pulmonary agent, it can cause pulmonary edema and eventually result in death. Chlorine was used as a weapon for the first time during World War I in 1915. More recently, it was used by insurgents to spread panic during the Iraq War.
Like its direct uses, chlorine also has some indirect uses. It is used to produce chlorinated solvents, chlorides, polymers, synthetic rubbers, etc., all of which have multiple uses of their own. Similarly, it is also used in production of several commercial products, including computer hardware, silicon chips, pesticides, insecticides, metals, paints, plastics, refrigerants, solvents, etc., as well as medical devices, like intravenous drips and heart catheters. Even the polycarbonate which is used to manufacture bullet-resistant glass is made from chlorine.
Chlorine easily dissolves in water to form a mixture of hydrochloric acid, which is used in production of chlorides, fertilizers, dyes, as well as disinfectants that are used to treat food preparation surfaces. An excellent oxidizing agent, chlorine is also used for bleaching in the paper manufacturing and fabric industries. It is also used for the extraction of bromine.
In the human body, chlorine is present in form of soluble salts referred to as chloride. Along with sodium and water, chloride works as a mineral electrolyte and plays a crucial role in distribution of fluids throughout the body. It helps in maintaining the fluid balance, both within and outside the cells, and is also essential for maintaining the required blood volume and proper blood pressure.
With all these uses to its credit, it isn't surprising that chlorine is one of the most sought-after chemical elements on the planet. Millions of people succumb to waterborne diseases every year. If not for chlorine, things would have been much worse.