During the last one hundred years, the human race has experimented with many endothermic and exothermic reactions to further advance our civilization. Examples of exothermic reactions are the use of nuclear bombs and cigarettes. An example of an endothermic reaction is a chemical ice pack. There are other examples of endothermic reactions, such as the evaporation of dry ice and photosynthesis (chlorophyll is used to react with carbon dioxide plus water plus energy to make glucose and oxygen). We have used most of these reactions and many more in our every day lives.
The most important and influential exothermic reaction of our century was the use of nuclear weapons in WWII. The United States Government began the serious operation known then only as “The Manhattan Project.” The most complicated issue to be addressed in making of an atomic bomb was the production of ample amounts of “enriched” uranium to sustain a chain reaction. The bomb killed men, women, and children aimlessly. It killed both military personnel and civilians. On August 6 and 9, 1945, the cities of Hiroshima and Nagasaki were destroyed by the first atomic bombs used in warfare. Nagasaki has never been subjected to large scale bombing prior to the explosion of a nuclear weapon there. While the damage from these few bombs were relatively small, it created considerable concern in Nagasaki and a number of people, mostly school children, were evacuated to rural areas for safety, therefore reducing the population in the city at the time of the nuclear attack.
The impact on the environment was that the explosion of a nuclear bomb over a target such as a populated city would lead to immense and severe damage. The degree of damage would depend upon the distance from the centre of the bomb blast, which is called ground zero. The closer one is to ground zero, the more severe the damage
Beyond the immediate blast area, casualties are caused from the heat, radiation, and fires produced from the heat wave. In the long-term, radioactive fallout occurs over a wider area because of current winds. The radioactive fallout particles enter the water supply and are inhaled and ingested by people at a distance from the blast.
The social impact was that researchers concluded that radiation exposure had a negative impact on both outcomes. Survivors had an IQ loss of approximately five points, and performed at a decreased level in school .This result is supported by the evident decreased level of intelligence seen in large portions of the generation born during the first years after the war. The initial and long-term destruction from the atomic bomb did not only physically affect civilians in Nagasaki and Hiroshima. The aftermath of the bombs had an extensive psychological impact on both the survivors and their families. According to a book called Hiroshima Plus 20 the effects of radiation poisoning are horrific, ranging from purple spots on the skin, hair loss, nausea, vomiting, bleeding from the mouth, gums, and throat, weakened immune systems, to massive internal hemorrhaging, not to mention the disfiguring radiation burns. The effects of the radiation poisoning continued to show up until about a month after the bombing. In fact the bomb also killed or permanently damaged fetuses in the womb.
The political impact of the use of nuclear bombs was that Harry Truman’s decision to use this weapon that was opposed by many and extremely controversial. Many speculate that the in an aspect, the bomb dropping in Japan ended the war. The atomic bomb was considered a “quick” and even economical way to win the war; however, it was a cruel and unusual form of punishment for the Japanese citizens. On one hand, it meant a quick end to the war for the United States, and on the other hand, a slow and painful death to many innocent Japanese.
Another less prominent example of an exothermic reaction is cigarettes. They are exothermic because of the reaction of liquid ammonia with dry ice to form ammonium carbamate.
Cigarettes have caused a massive impact on the environment. Nearly 600 million trees of forest are destroyed each year to provide wood to dry tobacco. In Tanzania, an estimated 65 pounds of wood is needed to dry a pound of tobacco and in countries where wood isnt used, coal or oil is used for drying. Researchers estimate that by 2010, 87 percent of the world??™s tobacco will be grown in the developing world. Tobacco plants use more nutrients than many other crops, degrading the soil. Vast quantities of pesticides, fertilizer and herbicides are used on tobacco crops. Some crops require over a dozen applications of pesticides during the three-month growing period.
A common example of an endothermic reaction is a chemical ice pack, which usually contains water and a packet of ammonium chloride. The liquid inside the cold pack is water. In the water is another plastic bag or tube containing ammonium-nitrate fertilizer. When you hit the cold pack, it breaks the tube so that the water mixes with the fertilizer. This mixture creates an endothermic reaction because it absorbs heat. The temperature of the solution falls to about 35 F for 10 to 15 minutes.
Hot/cold packs are used by athletes to minimize swelling of injuries such as muscle and joint sprains. They are constructed of a large pouch containing a dry chemical plus an inner pouch of water. The hot/cold pack is activated by breaking the seal on the pouch of water and shaking the pack vigorously. This action mixes the water with the chemical starting the exothermic or endothermic reaction.
If the dissolving of the chemical in water is an endothermic process and absorbs heat energy, it is a good candidate for making a cold pack because this process will lower the temperature of the content of the pack. If the dissolving of the chemical in water is an exothermic process and releases heat energy, it is a good candidate for making a hot pack because this process will raise the temperature of the content of the pack.
As a result, endothermic and exothermic reactions are used in many different ways and commonly. An important example of an exothermic reaction is the use of nuclear weapons. Humans have benefited from this by using it in war fare. Another example is the use of cigarettes. An example of an endothermic reaction is an ice pack.
Bibliography (APA format)
CND – Peace Education- Health and Environmental Effects of Nuclear Weapons. (n.d.). Campaign for Nuclear Disarmament – Home. Retrieved February 7, 2010, from http://www.cnduk.org/pages/ed/hande.html
World War 2. (n.d.). World War 2. Retrieved February 7, 2010, from http://www.world-war-2.info/atomic-bomb/
Brain, M. (n.d.). HowStuffWorks “Cold Packs”. Howstuffworks “Home and Garden”. Retrieved February 7, 2010, from http://home.howstuffworks.com
Tips, L. (n.d.). Tobaccos environmental impact. Green living tips. Retrieved February 7, 2010, from http://www.greenlivingtips.com/articles/190/1/Tobaccos-environmental-impact.html