OpE+-+Environmental


 * Option E - Environmental Chemistry (Class of 2011, this is your 2nd Option)**

// Human activities involve intensive use of limited resources found in air, water and soil. Many of these activities produce waste products that build up in the environment to produce pollution with increasingly local and global effects. An understanding of this impact is essential within and beyond the study of chemistry. This option has many opportunities for discussing aim 8 issues and the international dimension. // ** Core material: ** E1–E8 are core material for SL and HL (15 hours). ** Extension material: ** E9–E12 are extension material for HL only (7 hours).
 * Option E: Environmental chemistry (15/22 hours) **

** E1 Air pollution - **** 2 hours ** E.1.1 Describe the main sources of carbon monoxide (CO), oxides of nitrogen (NOx), oxides of sulfur (SOx), particulates and volatile organic compounds (VOCs) in the atmosphere. (2) //Include both natural and anthropogenic sources. Equations should be used as appropriate.// E.1.2 Evaluate current methods for the reduction of air pollution. (3) //Examples include:// // CO - catalytic converters, NOx - control of fuel/air ratio SOx—alkaline scrubbing, limestone-based fluidized beds, particulates - electrostatic precipitationi, VOC's - catalytic converters //
 * Power Point Presentation: || Note Guide: ||
 * [[file:TED01 - 02.08.11 - E1 Air Pollution & Intro.pdf]] || [[file:TED01 - 02.10.11 - E1 Air Pollution Notes.pdf]] ||

** E2 Acid deposition - **** 1.5 hours ** E.2.1 State what is meant by the term acid deposition and outline its origins. (1) //Acid deposition refers to the process by which acidic particles, gases and precipitation leave the atmosphere. Both wet deposition (acid rain, fog and snow) and dry deposition (acidic gases and particles) will be assessed. Rain is naturally acidic because of dissolved CO2 but acid rain has a pH of less than 5.6. It is caused by oxides of sulfur and oxides of nitrogen. The equations for the burning of sulfur and nitrogen, and for the formation of H2SO3, H2SO4, HNO2 and HNO3, will be assessed.// E.2.2 Discuss the environmental effects of acid deposition and possible methods to counteract them. (3)
 * Power Point Presentation: || Note Guide: ||
 * [[file:TED01 - 02.10.11 - E2 Acid Deposition.pdf]] || [[file:TED01 - 02.10.11 - E2 Acid Deposition Notes.pdf]] ||

** E3 Greenhouse effect - **** 1.5 hours ** E.3.1 Describe the greenhouse effect. (2) //Greenhouse gases allow the passage of incoming solar short-wavelength radiation but absorb the longer-wavelength radiation from the Earth. Some of the absorbed radiation is re-radiated back to Earth.// //** TOK: ** Some people question the reality of climate change and question the motives of scientists who have “exaggerated” the problem. How do we assess the evidence collected and the models used to predict the impact of human activities? //  E.3.2 List the main greenhouse gases and their sources, and discuss their relative effects. (3) //The greenhouse gases to be considered are CH4, H2O, CO2, N2O and chlorofluorocarbons (CFCs). Their// // effects depend on their abundance and their ability to absorb heat radiation. // E.3.3 Discuss the influence of increasing amounts of greenhouse gases on the atmosphere. (3) //Examples include: thermal expansion of the oceans, melting of the polar ice-caps, floods, droughts, changes in precipitation and temperature, changes in the yield and distribution of commercial crops, and changes in the distribution of pests and disease-carrying organisms.//
 * Power Point Presentation: || Note Guide: ||
 * [[file:TED02 - 02.14.11 - E3 Greenhouse Effect.pdf]] || [[file:TED02 - 02.14.11 - E3 Greenhouse Effect Notes.pdf]] ||

** E4 Ozone depletion - **** 1.5 hours ** E.4.1 Describe the formation and depletion of ozone in the stratosphere by natural processes. (2) //Formation: O2 + uv --> 2O (radical) / O2 + O (radical) --> O3 Depletion: O3 + uv --> O2 + O(radical) / O3 + O(radical) --> 2O2.// E.4.2 List the ozone-depleting pollutants and their sources. (1) //Examples include chlorofluorocarbons (CFCs) and oxides of nitrogen (NOx).// E.4.3 Discuss the alternatives to CFCs in terms of their properties. (3) //Alternatives include hydrocarbons, fluorocarbons and hydrofluorocarbons (HFCs). Include toxicity, flammability, the relative weakness of the C–Cl bond and the ability to absorb infrared radiation.//
 * Power Point Presentation: || Note Guide: ||
 * [[file:TED02 - 02.14.11 - E4 Ozone Depletion.pdf]] || [[file:TED02 - 02.14.11 - E4 Ozone Depletion Notes.pdf]] ||

** E5 Dissolved oxygen in water - **** 1.5 hours ** E.5.1 Outline biochemical oxygen demand (BOD) as a measure of oxygendemanding wastes in water. (2) E.5.2 Distinguish between aerobic and anaerobic decomposition of organic material in water. (2) //Use redox equations as appropriate.// E.5.3 Describe the process of eutrophication and its effects. (2) E.5.4 Describe the source and effects of thermal pollution in water. (2)
 * Power Point Presentation: || Note Guide: ||
 * [[file:TED03 - 02.16.11 - E5 Dissolved O2 in H2O.pdf]] || [[file:TED03 - 02.16.11 - E5 Dissolved O2 in H2O Notes.pdf]] ||

** E6 Water treatment - - **** 2.5 hours ** E.6.1 List the primary pollutants found in waste water and identify their sources. (2) //Examples include heavy metals, pesticides, dioxins, polychlorinated biphenyls (PCBs), organic matter, nitrates and phosphates. **Aim 7:** Data banks and spreadsheets can be used.// E.6.2 Outline the primary, secondary and tertiary stages of waste water treatment, and state the substance that is removed during each stage. (2) //For primary treatment, filtration and sedimentation should be covered. For secondary treatment, mention the use of oxygen and bacteria (for example, the activated sludge process). Include the removal of heavy metals, phosphates and nitrates by chemical or biological processes// E.6.3 Evaluate the process to obtain fresh water from sea water using multistage distillation and reverse osmosis. (3)
 * Power Point Presentation: || Note Guide: ||
 * [[file:TED03 - 02.16.11 - E6 Water Treatment.pdf]] || [[file:TED03 - 02.16.11 - E6 Water Treatment Notes.pdf]] ||

** E7 Soil - **** 2.5 hours ** E.7.1 Discuss salinization, nutrient depletion and soil pollution as causes of soil degradation. (3) //Salinization: This is the result of continually irrigating soils. Irrigation waters contain dissolved salts, which are left behind after water evaporates. In poorly drained soils, the salts are not washed away and// // begin to accumulate in the topsoil. Plants cannot grow in soil that is too salty. Nutrient depletion: Agriculture disrupts the normal cycling of nutrients through the soil food web when crops are harvested. This removes all the nutrients and minerals that they absorbed from the soil while growing. Practices leading to amelioration of nutrient depletion may further contribute to environmental pollution. Soil pollution: This is the consequence of the use of chemicals such as pesticides and fertilizers. These chemicals can disrupt the soil food web, reduce the soil’s biodiversity and ultimately ruin the soil. The chemicals also run off the soil into surface waters and move through the soil, polluting groundwater. // E.7.2 Describe the relevance of the soil organic matter (SOM) in preventing soil degradation, and outline its physical and biological functions. (2) //The term soil organic matter (SOM) is generally used to represent the organic constituents in the soil, including undecayed plant and animal tissues, their partial decomposition products and the soil biomass. It includes: (1) identifiable, high-molecular-mass organic materials (for example, polysaccaharides and proteins.) (2) simpler substances (for example, sugars, amino acids, and other small molecules.) (3) humic substances. The functions of SOM can be broadly classified into two groups: (1) Biological: provides source of nutrients (P,N,S) and so contributes to the resilience of the soil/plant system. (2) Physical: improves structural stability, influences water-retention properties and alters the soil thermal properties.// E.7.3 List common organic soil pollutants and their sources. (1) //Examples should include petroleum hydrocarbons, agrichemicals, volatile organic compounds (VOCs), solvents, polyaromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), organotin compounds and semi-volatile organic compounds// // (SVOCs). **Aim 7:** Data banks and spreadsheets can be used here. //
 * Power Point Presentation: || Note Guide: ||
 * [[file:TED04 - 02.18.11 - E7 Soil.pdf]] || [[file:TED04 - 02.18.11 - E7 Soil Notes.pdf]] ||

** E8 Waste - **** 2 hours ** E.8.1 Outline and compare the various methods for waste disposal. (3) //Examples include landfills and incineration.// E.8.2 Describe the recycling of metal, glass, plastic and paper products, and outline its benefits. (2) E.8.3 Describe the characteristics and sources of different types of radioactive waste. (2) //Include both low-level and high-level radioactive waste.// E.8.4 Compare the storage and disposal methods for different types of radioactive waste. (3)
 * Power Point Presentation: || Note Guide: ||
 * [[file:TED04 - 02.18.11 - E8 Waste.pdf]] || [[file:TED04 - 02.18.11 - E8 Waste Notes.pdf]] ||

** E9 Ozone depletion - **** 1 hour ** E.9.1 Explain the dependence of O2 and O3 dissociation on the wavelength of light. (3) //WL = 242 nm O2 --> 2O(radical), WL = 330 nm O3 --> O2 + O(radical). The energy needed should be related to the bonding in O2 and O3.// E.9.2 Describe the mechanism in the catalysis of O3 depletion by CFCs and NOx. (2) //For example: CCl2F2 --> CClF2 + Cl(radical), Cl(radical) + O3 --> ClO(radical) + O2, ClO(radical) + O(radical) --> O2 + Cl(radical). AND NO + O3 --> NO2 + O2, NO2 + O(radical) --> NO + O2. The net effect is: O3 + O(radical) --> 2O2. // E.9.3 Outline the reasons for greater ozone depletion in polar regions. (2) //Consider the seasonal variation in temperature in the upper atmosphere. Refer to surface catalysis on ice particles.//
 * Topics E9-E12 are HL material only! **
 * Power Point Presentation: || Note Guide: ||
 * [[file:TED05 - 02.22.11 - E9 Further HL Ozone.pdf]] || [[file:TED05 - 02.22.11 - E9 Further HL Ozone Notes.pdf]] ||

** E10 Smog - **** 2 hours **


 * Power Point Presentation: || Note Guide: ||
 * [[file:TED06 - 02.24.11 - E10 HL Smog.pdf]] || [[file:TED06 - 02.24.11 - E10 HL Smog Notes.pdf]] ||

E.10.1 State the source of primary pollutants and the conditions necessary for the formation of photochemical smog. (1) //VOCs and NOx, temperature inversion, windlessness and bowl-shaped cities should be discussed.// E.10.2 Outline the formation of secondary pollutants in photochemical smog. (2) //Examples include NO2, O3, aldehydes and peroxyacylnitrates (PANs). The role of free radicals and sunlight should be\ emphasized. **Aim 7:** Three-dimensional and four-dimensional GIS techniques and data banks can be used.//

** E11 Acid deposition - **** 1 hour ** E.11.1 Describe the mechanism of acid deposition caused by the oxides of nitrogen and oxides of sulfur. (2) //Formation of hydroxyl radicals: H2O+O3 --> 2HO(radical) +O2 or H2O +O(radical) --> 2HO(radical) / HO(radical + NO2 --> HNO3 / HO(radical) + NO --> HNO2 / HO(radical) + SO2 --> HOSO2(radical) / HOSO2(radical) + O2 --> HO2(radical) + SO3 / (SO3 + H2O --> H2SO4)// E.11.2 Explain the role of ammonia in acid deposition. (3) //In the atmosphere, ammonia neutralizes the acids formed to a large extent, to form ammonium salts. Slightly acidic ammonium salts, (NH4)2SO4 and NH4NO3, formed in the atmosphere sink to the ground or are washed out of the atmosphere with rain. As NH4 + is deposited and enters the soil, nitrification and acidification can occur. NH4+ + 2O2 --> 2H+ + NO3- + H2O//
 * Power Point Presentation: || Note Guide: ||
 * [[file:TED07 - 02.28.11 - E11 HL Further Acid Deposition.pdf]] || [[file:TED07 - 02.28.11 - E11 HL Further Acid Deposition Notes.pdf]] ||

** E12 Water and soil - **** 3 hours **


 * Power Point Presentation: || Note Guide: ||
 * [[file:TED09 - 03.04.11 - E12 HL Further Water and Soil.pdf]] || [[file:TED07 - 02.28.11 - E12 HL Further Water and Soil Notes.pdf]] ||

E.12.1 Solve problems relating to the removal of heavy-metal ions, phosphates and nitrates from water by chemical precipitation. (3) //Given the equilibrium formed by a metal M and a non-metal X: MX(s)<-->M+ (aq) X_ (aq). The Keq for this system is given by Ksp = [M+][X−], and is called the solubility product constant. Students should be able to solve problems associated with this type of equilibrium, including the common ion effect.// E.12.2 State what is meant by the term cation-exchange capacity (CEC) and outline its importance. (2) //The amount of exchangeable cations in a clay is called cation-exchange capacity. Include equations// // as appropriate. // E.12.3 Discuss the effects of soil pH on cation-exchange capacity and availability of nutrients. (3) //Examples of nutrients include Ca, Mg, Fe, Al, P, N, S, Cu and Zn. Use equations as appropriate.// E.12.4 Describe the chemical functions of soil organic matter (SOM). (2) //Include the following:// //*Contributes to cation-exchange capacity// //*Enhances the ability of soil to buffer changes in pH// //*Binds to organic and inorganic compounds in soil// //*Reduces the negative environmental effects of pesticides, heavy metals and other pollutants by binding contaminants// //*Forms stable complexes with cations//

**Reverse Osmosis Process for treatment of saltwater:** media type="custom" key="9190116" **Wastewater treatment facitility:** media type="custom" key="9190130"