Chemistry and the Environment - Essay Example

Chemistry and the Environment Describe the general properties of the atmosphere known as troposphere, stratosphereand the ionosphere. Describe the composition of unpolluted air at sea level.   The unpolluted air or atmosphere at sea level is chiefly made of gases kept in place by the effect of Earth’s gravity at an average temperature of about 14 C. Nitrogen and oxygen predominantly comprise the Earth’s atmosphere at approximately 78.1% and 20.9% respectively while there exists trace amounts of certain elements as argon, water vapor, and carbon dioxide to account for the remaining 1%. Negligible quantities of dust, volcanic ash, and other particulates in solid form are also present in the atmosphere with the main gases to facilitate the formation of clouds. In general, Earth’s atmosphere assumes the role of shielding all living things against the sun’s harmful ultraviolet (UV) rays. It keeps the temperature balanced within 24 hours as well. At different temperatures, the atmosphere is further subdivided into layers beginning from the Earth’s surface where troposphere lies between 7 to 14 kms followed by the stratosphere reaching the 50-km altitude. This layer is conducive for airplanes due to stability and with increasing temperature, only minimal amount of water vapor and other components may be detected whereas the troposphere consists of weather occurrences. The ionosphere, on the other hand, makes less than 0.1% of the total mass of the Earth’s atmosphere and the sun’s energy is radiates at its fullest on this layer so that ionization takes place and molecules split as they undergo the process of gaining or losing electrons. (2) Explain what constitutes a good fuel. Evaluate the social value of fossil and alternative fuels and the use of unleaded petrol. What are the sources of pollutants from fuel combustion and what impact do they (COx, SOx, NOx and O3) have on the environment?  Essentially, a good fuel must be one that releases heat energy in huge amount when burnt besides the attributes of being less hazardous when used and stored. If the fuel is good, it would be least likely to generate toxic substances or pollutants with unpleasant odor in the environment and between renewable and non-renewable energy resources, renewable energy resources prove to be the chief source of good fuel. Algae-based biofuels for instance may constitute a renewable alternative fuel used extensively in generating electricity. Aside from the renewably extracted geothermal energy, biomass, hydroelectric energy, solar, and wind powers, good fuel alternatives are also available as bioalcohols, ammonia, vegetable oil, hydrogen, non-fossil methane and natural gas. This approach with more secure options may be perceived to remedy issues with health and environmental impact depending upon the number of industries that prefer usage of energy from a renewable source. The fact that It normally takes nearly 700 million years to produce fossil fuels out of decaying plant and animal matters fossilized upon exposure to extreme levels of heat and pressure establishes the social value of fossil fuels which pertain to fuels formed out of the organic remains of prehistoric plants and animals that undergo natural process of anaerobic decomposition and these fuels are chiefly comprised in coal, gas, and oil. Besides being a flexible non-renewable energy source, based on their structure, depositional environment, and thermal reactions, fossil fuels reflect the social relevance of drawing a potential attraction due to the fact that most of world’s reserves of oil and natural gas come from deformed rocks whereas a great quantity of coal may be derived from sedimentary rock layers that do not undergo deformation. By combustion or fuel evaporation, mobile sources that pollute the air are either on-road sources or non-road sources. “On-road” or highway sources pertain to vehicles used on roads for transportation of passengers or freight such as light-duty vehicles (LDVs), heavy-duty vehicles (HDVs), and transportation motorcycles which may be fueled with gasoline and diesel fuel, or run alternatively by alcohol or natural gas. On the other hand, “non-road” sources include gasoline and diesel-powered vehicles, engines, and equipment used for construction, agriculture, transportation, recreation, and several other related purposes. Either origins of pollution bear impact upon human health and environment due to the hazardous properties of NOx, COx, and SOx. As such, long-term exposure to noxious NOx may cause minor to severe damage in lungs, liver, and blood since NO-compound is capable of reacting with hemoglobin to yield meta-hemoglobin, its lethal form. When constantly exposed to low levels of NO2, reduced breathing efficiency may also result besides headache, coughing, and loss of appetite. Due to its major presence in the atmosphere through smog, the colorless and odorless O3 gas has been well noted for the risks it poses on human respiratory system. Asthma, emphysema, and reduced levels of resistance to infection may result out of contact with much O3 in the air which can instantly bring one to cough, breathe heavily, and yield further discomfort in the chest during respiration. When irritation of the airways by inhaling O3 proceeds on a frequent basis, chances are for the affected person to acquire premature aging of the lungs and obtain other heart and lung diseases too. Similarly, impaired lung function and associated respiratory diseases like asthma can be caused and worsened by the presence of SOx in the atmosphere. SOx emissions have been found to bring about negative impact on produce through forest vegetation as well as agricultural crops when decreased productivity or premature death and heavy losses in foliage occur. COx, likewise, may well contribute to global warming via the greenhouse gas CO2 in higher concentrations, causing extreme reduction in global air condition. Moreover, people are also confronted with the risks of ‘dyspnea’ or disabled breathing, dizziness, abnormal pulse rate and perspiration, restlessness, irritability, visual distortion, and even abnormalities in the muscle activities in the eye depending on the degree of toxic exposition to COx. (3) Explain the formation of acid rain from acidic gases and their effect on soils, plant life and masonry.  Basically, the acidic contents of gases SO2 along with nitrous oxides or NOx released in air due to vehicular emissions or fuel combustion form mixture with rain water once precipitation takes place. Nitric acid and sulphuric acid are generated upon reaction of NOx and SO2 with water vapor and sunlight, thereby creating the so-called acid rain. Acid rain is chiefly responsible for acid depositions that pose threat to plant life on land via imbalance of nutrients in soil after acids have combined with natural elements beneath grass and leaves as well as freshwater lakes and stream ecosystems which may suffer pollution derived from lowered pH in water. Equivalently, acid rain is corrosive to buildings, monuments, statues, and other man-made structures through brick masonry by selective dissolution of the glassy fabric by which the silica grains of a brick are held together. Sodium and calcium salts in water are dissolved by acid rain and are transported through brick pores embedding acidic salts that eventually weaken the composition of the masonry. (4) Explain the effect of CFC on the ozone layer in the upper atmosphere. Chlorofluorocarbons (CFCs) primarily move up to the stratospheric layer of the Earth’s atmosphere where they are decomposed by means of ultraviolet radiation and in this process, CFCs give off gases of chlorine and bromine which, in their free states, accelerate depletion and damage of the ozone (O3) layer in the upper atmosphere. With appropriate settings especially at an altitude conducive for ultraviolet rays to operate on splitting up CFCs, chlorine is particularly released in huge quantities resulting in the potential destruction of significant percentage of ozone as observed from an event in Antarctica. References Layers of the Earth's Atmosphere: Troposphere, Stratosphere, Mesosphere, Thermosphere, and Exosphere. 2012. Layers of the Earth's Atmosphere: Troposphere, Stratosphere, Mesosphere, Thermosphere, and Exosphere. [ONLINE] Available at: . [Accessed 28 April 2012]. What makes a good fuel? | SimpleChemConcepts | GCE O Level Chemistry Tuition Coaching Programme. [ONLINE] Available at: . [Accessed 28 April 2012]. ScienceDaily: Alternative Fuel News. 2012. ScienceDaily: Alternative Fuel News. [ONLINE] Available at: . [Accessed 28 April 2012]. Air pollution, Health effects of Ozone pollution, risks of Particulate Matter pollution. 2012. Air pollution, Health effects of Ozone pollution, risks of Particulate Matter pollution. [ONLINE] Available at: . [Accessed 29 Apr 2012]. Sulfur Oxides Effects | eHow.com. 2012. Sulfur Oxides Effects | eHow.com. [ONLINE] Available at:  . [Accessed 29 April 2012]. 2-Health Effects of Carbon Dioxide Gas : OSH Answers. 2012. 2-Health Effects of Carbon Dioxide Gas : OSH Answers. [ONLINE] Available at: . [Accessed 29 April 2012]. How Is Acid Rain Formed? -- china.org.cn. 2012. How Is Acid Rain Formed? -- china.org.cn. [ONLINE] Available at: . [Accessed 29 April 2012]. A material loss; acid rain is leaving its mark on buildings, statues, automobiles and other man-made structures | Science News | Find Articles. 2012. A material loss; acid rain is leaving its mark on buildings, statues, automobiles and other man-made structures | Science News | Find Articles. [ONLINE] Available at: . [Accessed 30 April 2012] The Ozone Hole-Chlorofluorocarbons or CFCs. 2012. The Ozone Hole-Chlorofluorocarbons or CFCs. [ONLINE] Available at: . [Accessed 30 April 2012]. Read More