June 24, 2010
Chlorine has an atomic mass of 35.453, atomic number 17, is a member of the halogen family (VIIA), and its symbol is “Cl”. Chlorine contains 17 protons and 18 neutrons in is nucleus. There are two isotopes for chlorine as well; Cl-35 and Cl-37. Chlorine was discovered in 1774 by Swedish chemist Carl Wilhelm Sheele. Sheele came upon chlorine when he put a few drops of hydrochloric acid (HCl), then known as muriatic acid, onto a piece of manganese dioxide (MnO2). This caused a reaction where the pricduct was a yellowish-green gas that would later be named chlorine. At this point Sheele thought that this gas contained oxygen and was some sort of oxygen compound, but it wasn’t until 1810 that the more handsome, British chemist Sir Humphrey Davy discovered that the gas was an element of its own. Davy named the gas “chloric gas” or “chlorine” after the Greek word “chloros” meaning “pale green”. Chlorine appears naturally in both the earth’s crust as well as in sea water. Though chlorine does not exist naturally as a gas, chlorine is obtained through a chemical reaction involving a sodium chloride and water mixture known as brine. When an electrical current is passed through the brine it reacts and breaks up the solution into chlorine, caustic soda and hydrogen gas. The reaction looks like this: 2NaCl + 2H2 ----- Cl2 + 2NaOH + H2. Not only is the chlorine exceptionally useful, but the caustic soda that is a co-product of obtaining chlorine is also used in soap, pulp and paper, and textile industries. Having such a useful “co-product” from obtaining chlorine has led to the Chlorine-Alkali industry to be successful.
Chlorine is used every day in a number of ways. Here is a bullet list of just five everyday uses that chlorine is found in. * Drinking water: Chlorine is crucial in the purification of our drinking water. It was first used in the late 19th century to control the spread of water-borne diseases such as typhoid, cholera, dysentery, and gastro-enteritis. These diseases had been the major killers of its time before water sanitation was used with chlorine. * Home Products and Swimming Pools: Chlorine based products are used in laundry bleach, dishwater detergents, scouring powders, paper towels, and all-purpose cleaners to kill common germs. In additions to home products, chlorine is used in swimming pools to kill dangerous microbes that could otherwise affect health. * Hospitals: Chlorine compounds are used to protect patients from infections through its uses in cleaning, disinfection and as an antiseptic. The abilities are used to do the following: *
Stops contamination of wounds and burns.
Disinfects dialysis machines.
Disinfect work surfaces, table tops and laboratories. *
Kills bacteria that can live in hospital water and air conditioning systems. *
Public Safety: Chlorine is used to make protective equipment for police officers and firefighters and in turn for the military as well. Here are examples of how chlorine based products effect the public safety field: *
Protective helmets, face shields, and spectacles.
Bullet-resistant “glass” and bullet resistant vests *
Communication equipment including radios, telephones, microprocessors and computer equipment. *
PVC pipe is made from chlorine compounds and is the most versatile polymer available.
Chlorine can be found in a number of compounds. Here is a list of twelve compounds chlorine is found in and how they are broken down. Sodium Chloride (NaCl)
NaCl is found naturally in salt deposits left over from the evaporation of ancient seawater. NaCl is salt, and its physical state is hard white granules, just like what you find in a salt shaker at a restaurant. Ammonium Chloride (NH4Cl)
The extra electron that is found in ammonium is then borrowed by the chlorine to make the bond, creating...
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