Oxygen Atom From The Ozone Molecule example essay topic

THE SCIENCE OF OZONE Ozone, though similar to oxygen chemically, is composed of three molecules of oxygen and is usually blue in color with a very strong odor. The atmosphere contains less ozone than the common oxygen. While out of every ten million air molecules, there exist about two million molecules of normal oxygen and only three molecules of ozone. Most of these ozone molecules are typically concentrated in the Stratosphere, the atmospheric layer that runs roughly from ten km's to about fifty km's in altitude. Even though the amount of ozone in the atmosphere is small, it plays a vital role in the atmosphere. The ozone layer protects the Earth and everything on it by absorbing the sun's UV radiation.

When the ozone is not at an atmospheric level and is at ground level, ozone proves to have toxic effects. ' Inhaling fairly low amounts of ozone can result in signs and symptoms such as coughing, congestion, wheezing, shortness of breath, and chest pain in otherwise healthy people. People with already existing asthma, bronchitis, heart disease, and emphysema may find their conditions worsen while inhaling ozone. Breathing ozone may also increase the risk of getting certain lung diseases.

People can recover from short-term exposure to low levels of ozone. However, breathing high levels of ozone or breathing low levels of ozone over a long period of time may have more damaging and longer-lasting effects. ' Ozone has also been found to have positive effects on people. It has proven to be a very purifying substance. Doctors are now aware that it has three powerful properties: 1.

It stimulates the immune systems through production of natural cancer-killing proteins called. 2. It improves oxygenation (delivery of oxygen to starved tissues) and metabolism. 3. It is a powerful antibiotic when applied locally. Ozone is made naturally in the atmosphere or artificially by using high voltages or ultraviolet rays.

Ozone and Oxygen work together efficiently to prevent the ultraviolet radiations reaching the earth's surface. The ultraviolet radiations with shorter wavelengths, such as wavelengths less than 242 nm, have sufficient energy to break the O-O covalent bonds in the oxygen molecules and are thereby used up by the oxygen molecules. 242 nmO 2 (g) (R) 2 O (g) Similarly, ultraviolet radiations with higher wavelengths, for example more than 242 nm to 320 nm, are used up in breaking the bonds between the oxygen atoms in an Ozone molecule. 242-320 nmO 3 (g) (R) O (g) + O 2 (g) As Oxygen cannot use up such higher wavelengths of the ultraviolet radiations, it is most important that the Ozone layer in the atmosphere is preserved without being destroyed.

This process of ozone is called 'Photolysis' which is a continuous process so that ultimately the sun rays that reach humans are of less intensity. Otherwise, such high wavelengths of the ultraviolet radiations cause many adverse reactions to humans like skin cancers, skin aging and even the failure of crops. But, Ozone, the protective shield of the earth has been observed to be depleting since several years. The first discovery of ozone depletion was in the Polar Regions of Antarctica and the North Pole. During winter the Polar Regions do not experience any sunlight, but the air present in these regions develops into strong winds called the 'Polar Vortex. ' As the temperatures in these regions fall below certain range these winds start getting very cold and ultimately form clouds.

These clouds are called the 'Polar Stratospheric Clouds' which are unusual in that they form nitric acid tri hydrate. With the further drop in the temperatures the cold water present combines with the nitric acid. What are left over are chlorine atoms. This key important reaction leads to the loss of ozone in those regions. This process requires cold conditions which favor the clouds to form which is why the Polar Regions were the first target. However, once these clouds are formed, depletion of ozone can take place even in warm conditions.

These are some of the chemical reactions in the polar stratospheric clouds that were discovered by Mario Molina: 'Molina's chemical formulas are as follows: (1) Cloo 2 + HCl ice Cl 2 + HNO 3 (2) Cl 2 + hv - 2 Cl (3) Cl + O 3 - ClO + O 2 (4) ClO + ClO + M - Cl 2 O 2 + M (5) Cl 2 O 2 + hv - Cl + ClOO (6) ClOO + M - Cl + O 2 + M (M) is a 'collision chaperone' (a hard surface) for N 2 and O 2, as put by Molina. The "hv" stands for the ultraviolet rays that the sun puts out. The net result of this series of complex chemical reactions is two ozone molecules (O 3) will be turned into three oxygen molecules (O 2). This is the heart of the explanation that CFCs are depleting ozone in Antarctica. The so-called 'ch loro-catalytic process' has scared the hell out the common people. There is, however, a major problem that has been ongoing for almost eighty years that is harmful to the ozone layer.

This problem happens to be the manmade chlorofluorocarbons that we have been releasing into the air through many different means. The first CFC's were invented for the intentions of being used as a safe non-toxic gas in refrigerators. The previous refrigerant compounds used prior to the chlorofluorocarbons were sulfur dioxide and ammonia. These compounds were very good at keeping the refrigerators cold, but since the compounds were poisonous and hazardous to people's health they needed to be replaced. The CFC compounds that replaced the sulfur dioxide and ammonia compounds were much safer to the health of everyone.

In few years, the use of these compounds was extended to various other things like propellants in the aerosol cans, solvents, as expansions gases in the production of foams, as heat exchanging fluids in air conditioners, and as working fluids in refrigerators. These compounds are so very much useful as they are stable compounds with low toxicity and low flammability and do not react with other compounds. Chlorofluorocarbons are a family of compounds mainly containing chlorine, fluorine and carbon. Their main important properties that make them effective in usage these days are: .

Low Flammability. Low Toxicity. Low solubility with the other compounds. Chemical stability There are many types of CFCs that are important to us. Dichlorodifluoromethane (CCl 2 F 2) is used in refrigerants and air conditioning units.

Trichloromethane (Ccl 3) is used in aerosol propellants such as hairspray or asthma inhalers. Trichlorofluoromethane (CCl 3 F) is used for making the bubbles in plastics which we use for storing contents in packaging. We also use Trichlorofluoroethane (C 2 H 2 Cl 3 F) in cleaning substances as it dissolves grease. However, many adverse effects of these commonly used products have been discovered.

Bristol University scientists, England, have found that the frequent usage of fresheners and aerosols can be harmful to infants and pregnant women. The following effects could happen: diarrhea, headache and depression. This is because of the release of volatile organic compounds. In addition, these aerosols deplete the ozone layer more due to the presence of CFC-based chlorine. The reason why CFC's break- down the ozone layer is pretty simple. The CFC's do not get back to the Earth's surface after they are exposed into the atmosphere.

However, at some point the CFC's make their way into the stratosphere with all of the oxygen molecules and atoms. In the stratosphere, all the molecules are exposed to the ultraviolet rays from the sun. When the CFC molecules are struck by the rays, the chlorine atoms break apart from the molecules. Now that there is a lone chlorine atom in the atmosphere, it bonds with oxygen atom that could have been bonded with an O 2 molecule to form ozone. The chlorine atom is also able to steal an oxygen atom from the ozone molecule. After another oxygen atom will bond with the oxygen atom from the chlorine-monoxide.

This will leave the chlorine atom free to de story more ozone molecules. The two oxygen atoms are bonded into an O 2 molecule and the chlorine atom is now free to continue the process again. Once the O 2 molecule is formed it cannot become ozone by bonding with another O 2 molecule. In order for ozone to be made once again the ultraviolet rays need to strike the O 2 into single oxygen atoms or the O 2 needs to find lone oxygen atoms that the chlorine hasn't already stolen. The chlorine atom is not in the stratosphere forever. When the lone chlorine atom reacts with methane (CH 4, ) it becomes HCl and the acid can be washed back down to the Earth in the form of rain.

Even though ozone takes up a very small percentage of the molecules in the atmosphere, we should not take it for granted. Without it we would not be here today. It has been proven to protect us from the ultraviolet rays from the sun, and now we are finding even more uses for ozone. It can be used medicinally as well.

Ozone is effective in treating rheumatoid, arthritis, allergies, and peripheral vascular diseases, and in many neurological diseases like Parkinson' disease. Ozone also has many industrial applications as well. Few of them include: Being a powerful oxidizing agent, it helps purifying water by destroying bacteria, virus as well as in reduction of heavy metals like iron and manganese. Ozone is extensively used as the manufacturing gas in many industries. In the waste water treatment industries, ozone is used to reduce the foul smell of the air. Many other uses of ozone include sterilization in food processing industries, in cooling towers of cold storage's, dye removal in textile industries, sterilization uses in bottled water and beverage industries and many more.

Hopefully, we will find even more uses for it since it can be artificially made and we have an abundance of oxygen. However, many scientists are worried about the depletion of the ozone layer. The ultraviolet rays are harmful to people and the crops on the planet as mentioned earlier. The Montreal Protocol is an act that was started in 1987 and amended after in 1990 and 1992.

The Montreal Protocol basically states that the uses of CFC's and products that can harm the ozone in the stratosphere are to be phased out by the year 2000. This is a worldwide act to allow the ozone layer to repair itself. It has been very successful in that most of these CFC's have been discontinued. However, because the life time of these CFCs in the atmosphere is very long, the chlorine levels would also take several years to decrease.

But as these chlorine levels decrease, ozone depletion would also decrease. There has also been an interesting proposal by the New Jersey transit for the members of New Jersey ozone action partnership for a special discounted ticket called 'Ozone Pass' on 'Ozone Alert Days'. This pass though available for the members aims mainly at the reduction of number of vehicles at that time and is usually favored as it costs only $2.00 for the round trip. Besides the nations of the world, every individual can contribute to the reduction of ozone depletion just by following certain conditions, some of which are: 1) Become members of organizations like the one mentioned above.

2) Maintaining the vehicles such as cars in good condition, reduce the amount of drives by carpooling or even more effective using public transportations. 3) Reducing the use of consumer products that release fumes. 4) Using water based paints instead of oil based. 5) Educate others about the possible consequences of ozone depletion and how every individual can make a difference. Many more can be done to reduce the pollution of the atmosphere. However, it is high time we get serious about the consequences we encounter if there is no stoppage to this grave problem.

It is just not the effort of Nations and governments, but of every individual, that shall make a difference.

Bibliography

1) Mc Farl and, M, and. Kaye. ChloroFluorocarbons and Ozone Depletion. New York: Pergamon Press, 1992.
2) "The Ozone Depletion phenomenon". Exploring Earth's Atmosphere. 1996.
Washington, D. C, National Academy of Sciences. 24 April. 2005 web) Environmental effects of Ozone depletion and its interactions with climate change: Progress Report 2003.
Photo chem Photoblog. sci., 2004, 3, 1-5.
web Progress Report 2003.
pdf 4) Eichmann, Kai Uwe. The Natural Ozone Layer. Roos, Fiona. ESPE RE. University of Bremen. web ozone. htm 5) Ferreira, Eduardo. Interesting Facts about the Antarctic Polar Vortex. FAE C. web) CFC's and Ozone Depletion. web) Ozone Depletion. The Process of Ozone Depletion. 2004 web.