Chem Test 2
Chem Test 2 CHEM1003
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This 27 page Study Guide was uploaded by Daniela DiGuido on Saturday January 17, 2015. The Study Guide belongs to CHEM1003 at George Washington University taught by Zysmilich in Fall. Since its upload, it has received 166 views. For similar materials see Chemistry for Non-Science Majors in Chemistry at George Washington University.
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Date Created: 01/17/15
Overview Units 58 11192014 Water in Numbers 0 70 of the planet is covered by water 0 60 of the body weight is water 0 50 of the blood is water 0 carries oxygen from the lungs to every single cell in the organism o carries C02 to the lungs to be exhaled o transports nutrients to all the cells 0 transports toxic substances waste away from the cells 0 77 of the brain is water 0 80 of the world s sickness is due to contamination of water suppHes 25000 people die per day due to waterborne diseases 0 40000 children die per day due to lack of water 0 in 2004 22 million deaths worldwide were attributed to unsafe water nine out of ten of these were children under ve years of age Where is Water Found 0 974 in oceans 259 in ice caps glaciers groundwater fresh water 0 014 in lakes rivers atmosphere soil moisture fresh water Where does Drinking Water Come from 0 surface water 0 lakes rivers and reservoirs usually not ready for drinking 0 ground water 0 aquifers pools of water trapped 50500 feet below the surface pure water 0 Of all of the possible drinking water 26 of the total 0 86 frozen in glaciers and ice caps o 01 located in lakes rivers and streams 80 used for irrigation and cooling of power plants Unusual Properties of Water Water Methane Melting point 0 183 Boiling point 100 162 Heat of fusion 33 06 Heat of vaporization 226 51 0 High melting point 0 High boiling point 0 Water expands when it freezes High speci c heat the energy required to raise the temperature of one gram of water by 1 degree Celsius High heat of fusion energy required to melt a given amount of water 0 High heat of vaporization energy required to vaporize a given amount of water 0 Excellent solvent for ionic and polar compounds H20 s Chemical structure 0 Oxygen has a higher electronegativity than hydrogen 0 Electronegativity measure of an atom s attraction for the electrons it shares in a chemical bond 0 Hydrogen bond 0 Very strong intermolecular interaction 0 Responsible for High boiling point without hydrogen bonds water would boil at 125 degrees Celsius High melting point High heat of vaporization High speci c heat Lower density of ice 0 Hydrogen bonding between two water molecules 1 all quot39 a I o The arrangement of H20 molecules in ice lce has an open hexagonal arrangement of H20 molecules 1 7 5 Li I i tier ii 39Ilu39ilu ltjl 7 EU 39 r li llwi 5 ultramm mm I Dgr gulf1 Lawn Consequences of the Unusual Properties of Water 0 High boiling point 0 Water is liquid at room temperature only common liquid on the surface of the Earth Lower Density of ice 0 ice forms on the surface of lakes and insulates the lower layers of water aquatic organisms are able to survive winter High speci c heat 0 Oceans and lakes are heat reservoirs that moderate daily temperature variations coastal areas have less extreme temperatures High heat of vaporization 0 Body heat can be dissipated by evaporation of small amounts of water perspiration o Summers are cooler near large bodies of water High heat of fusion 0 Releases large amounts of heat upon freezing Saves crops from freezing by spraying them with water Water as a solvent for ionic compounds 0 An ionic bond results from the powerful electrostatic forces that exist between oppositely charged ions lons are formed when atoms lose or gain electrons I i N5 r 9 This dissolving sill ssdium Gl llll ri in water s ght u L39h u Water Dissolves sodium chloride and other salts o oceans are salty and cannot be used for drinking water very expensive to purify agriculturalfertilizers 0 containing nitrate N03 and phosphate P04 3 ions 0 fertilizers runoffs pollute lakes and rivers Matter from decaying plants and animals 0 Biological contamination aerobic and anaerobic decomposition of water supplies Biological Contamination Water dissolves matter degraded by bacteria single cell organisms from decaying plants and animals Aerobic bacteria need oxygen 0 0xidize organic matter to carbon dioxide water and inorganic compounds such as nitrate N03 and phosphate P04 3 Act as fertilizers n Promote the growth of algae Deplete oxygen and lake die 0 When all oxygen from the water is depleted no life is possible 0 Only anaerobic organisms can survive Anaerobic bacteria reduce organic matter producing methane CH4 hydrogen sul de H25 and ammonia NH3 Chemical Contamination From Farms Factories and Homes Sewage Fertilizer runoffs Pesticides radioisotopes detergents toxic metals industrial chemicals Contaminants o Nitrates N03 From fertilizers runoffs Gets reduced to N02 n Blue baby syndrome 0 Phosphates P04 3 From detergents Promote algae growth 0 Volatile organic compounds VOCs From solvents cleaners fuels etc Bad taste and carcinogenic 0 Car Industry Production of steel water is lost by evaporation 4 The remaining 96 gets contaminated with acids grease oil and iron sats Chrome plating produce chromate CrO4 2 and cyanide CN Both are extremely toxic Ecological Cycles Inarganiie Water Puri cation 1 2 Coarse Filtration gets rid of the sh plants sticks cans etc Aluminum sulfate and calcium oxide are added they form a sticky gel of aluminum hydroxide which collects suspended dirt particles then settles Any remaining particles are removed by ltration through gravel and sand Aeration aerobic bacteria consume organic matter Disinfection to kill diseasecausing organisms Most common disinfectant Chlorine 2 ilurninurn aulfate l t glu 4 Aeratian aemlaie bacteria and ealeiurn eaitle Eat are ennau rne nanie matter added theyr term a atieky gel af aliu minam hearnettle alfIDng whieh ealleata eruaperlde dirt gantielea Ful llng then aettlea I gt E lDiainfeetia n ta ltiill dieeaaae eauainig organisms Heat eernnnam diaiinfeetant ell39Ilriinie leLIHI39 Hardc MELI intake Guam 39 ltratien in In In 1 Gearae filti39tiezn gets rid er iiah plahta atieita eana l v quot Bran remaining grtielea are reminved by fillratinrl threugh gravel am aainti Common Disinfectants Disinfectant Advantages Disadvantages Chlorine cheap bad taste and odor residua action forms residual by products chlorinated compounds such as chloroform Ozone smaer quantities are expensive needed more effective against bacteria and water borne viruses no residual byproducts no bad taste and odor no residual action Ultraviolet Light fast no residual byproducts no bad taste and odor hard to apply for large scales Chloramines cheap effective residua action no chlorinated by products Acid Rain Atmospheric and environmental chemistry 0 Air quality localized in cities 0 Ozone depletion global 0 Greenhouse effect global 0 Acid rain regional Acid deposition 0 Acid rain 0 Acid snow 0 Fog 0 Dry deposition acidic solids Mass Mole and Avogadro Atomic mass mass in grams of the same number of atoms that are found in exactly 12 grams of carbon12 Avogadro s number number of atoms in exactly 12g of carbon12 Na602 X 10quot23 Mole an Avogadro s number of anything Molar mass the mass of one Avogadro s number of whatever particles are speci ed 0 C024401 gmol Concentration and pH 0 Concentration amount of a substance dissolved in a given volume of a solvent Molarity M number of moles of a substance present in one liter of solution 0 In pure water the molarities of H and OH are equal M 10 X 10quot7 M o The addition of an acid or a base to water changes these concentrations 0 Acidic solutions 0 Neutral solutions 0 Basic solutions H molarities can range from more than 10 molL to less than 00000000001 molesL 0 Its more convenient to use a logarithmic scale 0 pHloth If Mhgt10quot7 M D pHlt700 acidic solution 0 If Mhgt10quot7 M l pH700 neutral solution 0 If Mhgt10quot7 M D pH gt700 basic solution Pure Rain l pH55 61313 H 2 Htr gji Howl4m What is the origin of the extra acidity Where is rain abnormally acidic 0 Low pH values in heavily industrialized areas Northeast and Ohio River Valley 0 What does acidic rain contain 0 Analysis of acidic rain shows presence of nitrogen and sulfur oxides What s the origin of these other contaminants 0 Emissions of sulfur dioxides are highest in regions with many coal red electrical power plants steel mills o Nitrogen dioxide emissions found in large urban areas with high population and heavy automobile traf c lilyimam inn Ei 39 l lh39i 51 pl mmummtnta ma a ii lJii iil39l39lfil Jami Emmi Laimarmrir 5mm 51 mm quot1139 l i IIJI I I quot11 i i I I I iLIII1 Tun 29511515qu 9913 C553 39uLi39J How do sulfur and nitrogen oxides affect the acidity of rain Oxide of nonmetals water acidic solution Oxide of metals water basic solution Where do sulfur oxides come from 502 and 503 l from combustion of coal 0 Coal is mostly carbon but it also contains hydrogen oxygen nitrogen sulfur and small amounts of silicon sodium Once in flihe atmosphere 2 5 2 g 32 lg w 2 Eli In Los Angeles the concentration of 502 in smog is very low and so is the pH Where do nitrogen oxides come from 0 They come from transportation Gasoline does not contain nitrogen but air does H 4 DE 2 Hr lg nitric oxide E H Q 53 91 2 H2 El nitrogen dioxide anthropogenic human impact on the environment Effects of Acid Rain 0 acid rain affects 0 materials creates limestone calcium carbonate creates rust iron oxide the acid H is a catalyst accelerates the corrosion process 0 visibility summer haze microscopic aerosol particles of sulfuric acid ammonium sulfate and ammonium hydrogen sulfate 0 human health acid droplets deposited in lungs affect sensitive tissue 0 lakes streams and forests aluminum is the most abundant metal and the third most abundant element in the earth crust acid rain increases the solubility of Al n if pH drops from 6 to 5 the Al concentration in a lake may increase lOOOfold sh exposed to high Al concentrations develop a thick mucus on their gills and suffocate Al attacks tree roots preventing absorption of nutrients Nitrogen oxides attack the waxy coating on leaves and H depletes nutrients Acid rain washes out minerals essential for plant growth like potassium calcium magnesium etc Control Strategies 0 Reduction of NOx l produced by motor vehicles small individually owned and mobile 0 Catalytic converters 2N0 l N2 02 0 Eliminate internal combustion engines 0 Electricpowered vehicles 0 Reduction of SOZ l produced by coalburning power plants and factories Coal switching use coal with lower sulfur content 0 Social and economic impact 0 Coal cleaning remove sulfur from coal l easy but expensive Neutralize SOZ emissions Scrubbing l very expensive e mi l lei so oa lei 2 e eel use e e Politics of Acid Rain 0 Strong and effective lobbies from electrical power industry and high sulfur coal producers Clean air act amendments if a company exceeds the maximum level of emissions can be ned up to 25000 per day 0 Trading 502 emission credits 0 Companies are assigned emission allowances o If a company emits below its allowance it can sell credits to other power plants unable to meet their allowance Before the emissions cap and trade program n if 73939739l39 l W Ijrira 17 20000 Lone 20000 mus ernilteo enitled Uriii Llnrfi 2 With a oao requiring 50 if reduotion in emiseione id quotHfi 11 7 5v n f I quot 39 quot 00001015 moon Lorie milieu emilted Ur lil Linill 2 With emissions trading after the 50 e211 5000 1on5 traded 539 1 PERrapt quot eooo lions 39 ieooo lone Ellquotquotiil19 emitbeo Unit 1 Lllquot1il 2 radioactivity spontaneous emission of radiation from certain unstable elements Isotopes and Radioisotopes The nucleus of an atom contains neutron and protons and we collectively refer to these particles as nucleons Atoms of a given element all have the same number of protons atomic number but different isotopes have different numbers of neutrons Isotopes are distinguished by their mass numbers total number of nucleons Radioactive nuclei are called radionuclides Atoms containing radionuclides are called radioisotopes Radionuclides spontaneously decay by emitting particles and electromagnetic radiation Type of Radioactivity Herre 730355 term 031mm 7 70mm galore fe at 2 He metal 01 tiirete till 00005 nil eveeimne 4035 5001500 1quot 0 15 Halanemia 5 ereolrernegneho feeelm o epeecl of fght 00000 Ernie Pmia n 3 harlng m canalan in Shanna in i39diiljntir it NumbEr Mags Plumber Huf l i F f rJIEiu t iian Alpha emissiumi palIE E 1 2 Eats 3mm w H all Hi 1l Gamma emi s mm 2T i Eli Pu mm Cine 1 Eli l Beta ea 1 Eli Chemical Reaction Atoms retain their identity Reactions involve only electrons and usually the outermost electrons Reaction rates can be speeded up by raising the temperature Energy absorbed or given of in reactions is relatively small Mass is conserved The mass of the products equals the mass of starting material Nuclear Reaction Atoms usually change from one element to another Reactions involve mainly protons and neutrons It does not matter what the valence electrons are doing Reaction rates are unaffected by changes in temperature Reactions sometimes involve enormous changes in energy Huge changes in energy are accompanied by measurable changes in mass Beta Decay A type of radioactive decay in which a proton is transformed into a neutron or vice versa inside an atomic nucleus This process allows the atom to move closer to the optimal ratio of protons and neutrons Alpha Decay A type of radioactive decay in which an atomic nucleus emits an alpha particle and thereby transforms into an atom with a mass number 4 less and atomic number 2 less Positron Emission Or a beta plus decay A type of radioactive decay and a subtype of beta decay in which a proton inside a radionuclide nucleus is converted into a neutron while releasing a positron and an electron neutrino Mediated by the weak force Electron Capture o A process in which a protonrich nuclide absorbs an inner atomic electron thereby changing a nuclear proton to a neutron and simultaneously causing the emission of an electron neutrino Various photon emissions follow as the energy of the atom falls to the ground state of the new nuclide both position emission and electron capture decrease in 1 unit the atomic number with the change in mass number Gamma Radiation Gamma rays consist of highenergy photons It accompanies nuclear reorganization Hiatusr annihilation e g r Band of Stability When isotopes are plotted according to numbers of protons and neutrons all the stable nuclei lie within the band 0 More protons require more neutrons to provide a compensating nuclear strong force and to dilute the electrostatic protonproton repulsion The plot stops at element bismuth because no element above this has a stable isotope Isotopes with atomic number greater than 83 tend to be alpha emitters Isotopes occurring above and to the left of the band of stability tend to be beta decay Isotopes lying below and to the right of the band are positron emission or electron capture Radioactive Decay We can know if an isotope is going to decay or not we do not know when 0 Half life period in which onehalf of the original number of atoms undergo radioactive decay to form a new element 0 Fraction of atoms left after n halflives 12quotn Radioisotopic dating Carbon14 dating artifacts derived from plants and animals Carbon14 is formed in the upper atmosphere by bombardment of N14 by neutrons from cosmic rays all in c tgi 1H this process leads to steady concentrations of C14 in Earth s C02 plants incorporate C02 in their cells photosynthesis when organisms die there s no more C14 incorporation Nuclear Energy 0 nuclear reactors nuclear bombs nuclear ssion a process by which the nucleus of an atom is induced to split into two or more fragments by some external source 0 nuclear reactions mass is not conserved o releases a lot of energy loss of mass Nuclear Fission chain Reaction The Making of an Atomic Bomb 1 How to sustain a nuclear ssion chain reaction 0 critical mass 4kg neutrons needed to be captured by ssionable nuclei before they escape the pile 2 How to Enrich Uranium235 at least 90 pure U235 needed gaseous diffusion a technology used to produce enriched uranium by forcing gaseous uranium hexa uoride through semipermeable membranes 0 this produces a slight separation between the molecules containing uranium235 and uranium238 Gas centrifuge uranium enrichment o UF6 gas is whirled inside complex rotor assemblies and centrifugal force pushes molecules containing the heavier isotope to the outside 3 How to make Plutonium239 by bombardment of U238 with neutrons 4 How to build a bomb l LI Diagram of a Nuclear Power Plant A l lll li fliill ll 39 Etllll39 ll High 7 Quin In E39IVIJEIHFrg REEill FiTi 39 lilzilll39li imam Controlled Fission 0 Nuclear reactors use only 35 of ssionable U235 in the form of uranium dioxide U02 Neutrons given off during the ssion on U235 are absorbed by atoms of U238 cadmium and boron no build up of a neutron stream No critical mass of U235 Risks from Coal and NuclearPowered Electricity Generators 39T b l i 1E Illnimrll T5 lll39 mallilhh39 fiz llllii l Inn3112 Eifli39Hl Final 39ILII I39E39illiF b39 LIEi39iila39llimlillil39liifl iEIIE din 135 uiIlill J uniand Iliyll I39aI 1 1 lms Trim L39Iim l aim3 Huclean39l mmrt Elli rmly Hi i39timii39h Ir r EihLmlill Erantrug illill iilliquot IJIIFl liil39 IJI l liIuILL lcilfta RiulithFllilllillilll I1 vtiil J 39iFrIiflrz iiiJIHIIr39ir39jlli IIJI39EJ IIE it39LE IIIEi L Innnuimkm ul Pt I EIL1IEIZIILSFJ39 L39I III l IL5 JJIEIHI IL llll samIIHIuEiTtcli39lllliufl titla Iliaup Hint lain I lift ITLEEIn39l Ill39 liill1 ij quoti 39 I f ifnlllhlllgf l twinll idiilh IIiJ Mid quotHull s49 mi Elliilru lll I u Lingch ir39Lii39uiii39i39llsllgi39 iII eIIEE39iIlj fr zar imlmim zlr IL39E llifmi llg JIEIEE39IlI39EJIIJITEI illlJillhll 9 Eli rl39 IEll39 IZ ELL aliquot iII39aII1i chiI Biological Effects of Radiation Highenergy radiation such as alpha beta gamma and x rays is known as ionizing radiation because it causes ionization of atoms and molecules 11 m A HP l rlli IJ39L39EIIEi39rtJJ1E39I EIIiEEEill tzulli Lin3E Mrsg lliiilma 5II L FI39JJII3EE Iiihie quotll39li 39 EL WM LHlaknni marr nudgmm all LWH39FF12iE iEP391iiDI FIjIIJFi39H39PIL i39lEE E39Jth rials IllELI CI nElrl hlla39lmlilulLaI liillllJEil39fJ ij39lillau MilliI ionization of molecules in a living system generates species known as free radicals 0 free radicals are very reactive and can initiate a large number of undesirable chemical reactions that are potentially disruptive to normal cell operation 0 the extent of damage done by radiation depends on Penetrating Power Power of rays the type of radiation the length of exposure whether the exposure is external or internal 0 alpha is the weakest stopped by the skin although internal exposure to alpha radiation can be extremely dangerous 0 Beta is in the middle only a cm beyond the skin s surface 0 Gamma is very strong high penetrating power Physiological Effects of a Single Dose of Radiation TjiIIIIuI ITlull Illnia 1H1 ILiIul39ly39 II TilTH39I a 5 4231 Han wl menwifi lc galley Jfla Ftl H15 jm t39tfl39iite i rltitiJl 39Evl count nhLquotI39Lu slightly iM Ili39ij HIEt ii MinnieHm t l39t39al39l m Willi1 lairml gull 39iilm1 Fifiin l i39i39lzgl 39i LIIIPEJE M lhl39 e39E39J 3939Iin1iiiiri lime iI Haiiil39 F f jlz l 1 ff5 H1 1lquotilllE39Iliilitinllgq lilacsI m l1ll391h1li1i39nla39lialli39l iquot l i 39 39Ial ilkml Sources of Background Radiation RadonRn Radioactive noble gas chemically unreactive inhaled and exhaled without any chemical consequences However its halflife is short 382 days and its alpha decay product is an isotope of polonium aa n 2la FtlHlE Polonium is an alphaemitting solid that can become trapped in the lungs exposing delicate lung tissue to longterm harmful alpha radiation Nuclear Fuel and Nuclear Waste Nuclear reactors use U02 only 35 U235 What happens with the rest 95 of U238 353 1 235 E3 3932 guru 2 le Breeder reactors convert U238 into Pu239 Spent fuel material remaining in the fuel rods after they have been removed from the reactor After about 34 years of use the U235 concentration in the fuel rods of a power reactor drops to the point where it is no longer effective in sustaining the ssion process Nevertheless they still contain highly radioactive isotopes such as Pu239 l131 Cs137 and Sr90 highlevel nuclear waste HLW Nuclear Waste in Numbers Total accumulated by the US DOS 350000 mquot3 Spent nuclear fuel SNF HLW from nuclear reactors Nuclear power plants have shortterm nuclear waste storage facilities 25 years Pu239 halflife 24000 years It takes about 250000 years for the radioactivity to drop to the background level How Will we Dispose of Waste from Nuclear Plants Experts throughout the world agree that the most feasible and safe method for disposing of highly radioactive materials is to store them deep underground 0 Site selected 0 Must safely contain the radioactive material for extended time 0 Must prevent the radioactive material from entering underground water supplies Yucca Mountain Project Nevada 0 Determine if Yucca Mountain Nevada is a suitable site for a spent nuclear fuel and highlevel radioactive waste repository Combustion Reactions 0 Fossil Fuels E i592 ii a 3923 ii aibcnr HEEEEI EH 3929 2 Es Eli ail31 31 E H IE WEHTJE lrau al gas EEH5 Dalig EEEH a Hg i l c L 1E I i u Elam quot r lgi l i f Are there any alternatives 0 Hydrogen H2 nonfossil fuel Hg 9 3 2 EH Halli 0 Can hydrogen be used as a fuel Yes and its actually used to launch the space shuttle and other rockets o Is hydrogen a safe fuel Unfortunately H2 is very reactive and is usually found combined with other elements ie H20 o Is hydrogen readily available Hydrogen is the most abundant element in the universe o If not how can we obtain hydrogen Electrolysis of water passing a direct current of electricity of suf cient energy to break OH bonds in water 95 M Ham ill 3 H9quot lg Eli ill Where do we obtain the electricity to split water from n Burning fossil fuels 0 The production of electricity from fossil fuels is not an ef cient process The ef ciency of a power plant is about 60 o If we account for the energy lost in the transmission over power lines we would be needing twice the energy to form one gram of H2 than the energy we would obtain rom burning it Thermal decomposition of water not very promising Reaction between water vapor and Cs from coal From natural gas CH4 o Is the combustion of hydrogen pollution free FuelCeHs Chemical energy is directly converted into electricity Oxidationreduction reactions Oxidation 0 Loss of electrons Harm 13 Hraqjaj 3 0 Reduction 0 Gain of electrons gigi2Hiaqi2e H m m I i139u Other Fuel Cells use Methanol Uiid lll l HEBEl EH JHEEIqJ G a gj i E Friam i Ea Fttluclfitri 123 2 H lien 5 Ear Hg l3 0 Fuel cells bene ts High ef ciency Low fuel consumption Noiseless Minimal or no pollutant emission Fuel cell vehicles driven by methanol produce small amounts of waste gas they could lower the carbon dioxide emissions by about one third No environmentally harmful nitric oxides no sulfur dioxide and no soot particle are produced Emissions of hydrocarbon and carbon monoxide are hardly detectable Batteries electrochemical cells Devices that convert the energy of chemical reactions into electrical OOOO energy 0 Alkaline batteries ElxiclatiEn Ems E H gm I En ilj is a 3925 adunlien 2 l n risi s li39lEElajl 2e t lalnf i agi E EHDEEJIIEH Eni 1 E familial 1 HE39S5 EJ1l 39HIEuEl MHEUSLEJ r1 39EIZIII n mac5 Electrical Vehicles EV Nissan leaf 0 100 miles on a single charge 0 charging 30 minutes to 80 at a 480 volt quickcharge station 8 hours at 220240 V depending on amperage 20 hours at 110120V o the electrical grid is much cleaner than burning gas 0 the grid will get cleaner over time unlike gas Hybrid Cars 0 15 Liter gasoline engine nickelmetal hybrid batteries electric motor electric generator 0 50 less carbon dioxide emissions and very low nitrogen oxides emissions no recharging necessary the kinetic energy of the car is used to charge the batteries during deceleration and breaking ii infers x g I l i 3 39quotir Euwerriima a39El iiEIEE Hytii39i quot ehltlea What is Renewable Energy Fossil fuels are nonrenewable they draw on nite resources that will eventually dwindle becoming too expensive or too environmentally damaging to retrieve Renewable energy resources are constantly replenished and will never run out Most renewable energy comes either directly or indirection from the sun 0 Solar energy Hydropower Wind energy Geothermal Ocean energy 0 Biofuels 0000 Solar Energy Each day the Earth receives more energy from the Sun than is consumed by our planet s six billion inhabitants in 27 years What are the most ef cient solar energyharvesting devices on Earth 0 Plants and other photosynthetic organisms How do humans harvest solar energy 0 Photovoltaic cells Semiconductors Minerals that conduct electricity under certain conditions Silicon 0 Schematic of a Photovoltaic solar Cell M nahmu Com glass Sunni ht Tmmcpamln l antitankwe r Amnim uc lint L t1tl l mg 39Frunl UEJlllEaiLCl Back mutual Photovoltaics 0 Bene ts 0 High reliability operate for long periods itte maintenance 0 Low operating costs fuel is free 0 Environmental Bene ts no fuel no moving parts Clean and silent o Modularity constructed to any size 0 Low Construction Costs placed close to where the electricity is used The Hydrologic Cycle 0 The energy of this water cycle is driven by the sun 0 About 25 of the solar radiation reaching the Earth powers the water cycle Hydroelectric Power Hydroelectric Dam ll lj MIU39ITal 39ld39lullh L FEIJIN Lung Ekaterina Pmm lLlll39ll 0 Advantages o Other than manufacture of machinery and materials and construction of facilities hydroelectric power does not produce any emissions 0 Low maintenance and low operational costs 0 Large reservoirs may also present recreational opportunities 0 Disadvantages 0 Changes to natural river ows Degraded water quality Blocking of season sh migration Impacts to sheries Widespread ecosystem damage from ooding large areas of land Wind Energy or Wind Power 0 Good wind resources have an average annual wind speed of at least 13 miles per hour Advantages 0 Wind energy is a free renewable resource 0 Wind energy is also a source of clean nonpolluting electricity Wind plants emit no air pollutants or greenhouse gases Economic Obstacles o The technology requires a higher initial investment than fossil fueled generators 0 Environmental problems 0 Noise produced by the rotor blades 0 Visual impacts 0 Birds and bats are killed by the rotors Other drawbacks 0 Wind is intermittent and it does not always blow when electricity is needed 0 Wind cannot be stored 0 Good wind sites are often located in remote locations far from areas of electric power demand Geothermal Plant 0000 EmiEEi 13 ma llbsflullwe hr Ii ll Eli h39l ltl39aFc IRE lhrt i39 tal a llbellulW hr i Em IIrl EllEmmi Eatthermal o disadvantages o the supply of steam from geothermal reservoirs is limited and this resource may become unusable without management and preservation efforts 0 environmental harms potential contamination of groundwater with sul des and other pollutants if well casings are not done properly carbon dioxide and hydrogen sul de are released by geothermal plants despite the absence of fuel burning processes many geothermal reservoirs are located in sensitive and pristine wilderness areas that should not be disturbed Costs and Expenses for Different Types of Energy Production U395 ml l 5 l l itWilli Wiginn Plant nal for Flame that EEQHM Eommerciai Emigration iBE l EM WEE Dollars mm I I nlllllll 39l39l I39I39IJIllll i39l39 lllllll39l39l39l I IIIIIlluzmrI I Fl39lllll tl l39l I Imu al l gunmanHucuiccumssj InquuucuuuiAuscs ua A A A I I H InThDuzanrdasf A hi LI g I FWIJiuelEd yearn Nuclear Emil Hyzl39lbEii rli turbine Average lawn Production paneea Imtwmmr Miflsi iii39LilHFIlm 1W1 Will Gas nu ma a mailscale H 39 f railElam Fmal lualeI Wired1mm EllE 3111 Arti cial Sequestration Carbon capture in power plants 0 Scrubbing aminebased solvents hydroxides Direct Ocean Injection 0 Carbon dioxide is pumped direction into the water at depth and expected to form lakes of liquid C02 at the bottom Mineral Sequestration 0 Carbon is ed in a nonreactive mineral form fg slfl h 1 3m 4 3mm l 25ft 2 gage 4inFt39Lljrquotig i g lzit g u Hiring ma ElJiL 33tg gITUHinJiEngli iE ag ySi grIa g i LI m ltn In Geological Sequestration 1 C02 is pumped into disused coal elds displaces methane which can be used as fuel 2 C02 can be pumped into and stored safely in saline aquifers 3 C02 pumped into 0 elds helps maintain pressure making extraction easier F39El f LilLIE I infer i Clean Coal Technologies CCT When burned coal is the dirtiest of all fossil fuels A range of technologies are being used and developed to reduce the environmental impact of coal red power stations Coal Preparation 0 Coal arriving at a power plant contains mineral content that needs to be removed before it is burnt Coal Washing o 1 Coal is ground into smaller pieces 0 2 Coal is fed into barrels containing a uid that has a density which causes the coal to oat while unwanted material sinks and is removed form the fuel mix 0 3 Coal is then pulverized and prepared for burning mm WAEHIIEE 539 HF 11 a ti n7 Coal Gasi cation Integrated Coal Gasi cation Combined Cycle IGCC Plant 1 Coal burnt to produce syngas COH2 2 Syngas burnt in combustor 3 Hot gas drives gas turbines 4 Cooling gas heats water a quot339 Eiect utiw fi fi ll39li mm 29 9231 ridding 3W h Wt in IGGC systems coal is not combusted directly but reacts with oxygen and steam to form a syngas after being cleaned it is burned in a gas turbine to generate electricity and to produce steam to power a steam turbine 0 coal gasi cation plants are seen as a primary component of a zero emissions system However the technology remains unproven on a widespread commercial scale Removing Pollutants burning coal produces a range of pollutants that harm the environment Sulfur dioxide acid rain nitrogen oxides acid rain and groundlevel ozone and particulates 502 0 Wet scrubbers REHEIE39EHTHWLFHEDI 7 ELMFFEC iEBEiiEQ ILFEiIH 39IHLiFiCIJ It39i FIJF jnl magicl 1am Quasi EifE iEFJ Emmi L ili li jz in 77 7 ELEMni39 iiiiil ui l 39FE Fit2 flair GTLEJHI Li SEEIJIiII i irl ijl r NOx 0 Low NOx burners Restrict the amount of oxygen available in the hottest part of the combustion chamber where the coal is burned Particulates emissions L E i 7 e I LnDH Emucat uf Wquot P m i 7 i an 11 rijaggi39 m u agrmjj 3 Ecliiqtrimli 5 uj mram atiii 12 Calif 3 In 239 9539 1 E 31LLE ERIE a
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