St. George's College
Subject: 7th CHEMISTRY
Class: Acid Rain Date: November 9th
Teacher's notes
Objectives
Vocabulary Link and Learn
In‐Class Survey
Prepared by
2009 1
7th Beethoven ‐ Acid Rain Name
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Name
Ariana
Luis
Gabriel
Andrea
Andrea
Sebastián
Abraham
Ivanna
Giacomo
Camila
Fabiana
Carlos
Sinead
Aarón
Liliam
Paola
Francesca
Enrique
Rodrigo C.
Alessandra
Andres
Irma
Stefano
Sophia
Jean Pierre
Naomi
Diego
Kiara
Rodrigo H.
Christopher
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7th Mozart ‐ Acid Rain Name
Reward Blackmarks
Name
Nicole
Roberto M.
Luis
Giancarlo
Luciana
Fiorella
Antonella
Gabriela
Valeria Ch.
Steffano
Valeria C.
Javier
Sylvana
Roberto R.
Analucía
Diego
Camila
Luis Fernando
Franco
Sebastián
Ramiro
Julio
Sara
Sherley
Alicia
César
José Luis
Vilma
Sergio
Alessandra V.
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New knowledge beginning......
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ACID RAIN
pH
Rain from an unpolluted atmosphere has a pH close to 6.0 (slightly acidic). This acidity is due to the reaction of water vapour and non‐metal oxides in the atmosphere, such as carbon dioxide and nitrogen oxide, forming dilute acids. • Carbon dioxide reacts with water to form carbonic acid: CO2(g) + H2O(l) H2CO3(aq) Since carbonic acid is a weak acid it partially dissociates: CO2(g) + H2O(l) H+(aq) + HCO3‐(aq) • Nitrogen dioxide reacts with water to form a mixture of nitrous acid and nitric acid: 2NO2(g) + H2O(l) HNO2(aq) + HNO3(aq)
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ACID RAIN
pH
Acid rain has a pH below 5.6 due mainly to the reaction of water vapour with sulfur dioxide and the oxides of nitrogen. Sulfur dioxide reacts with water to form sulfurous • acid (H2SO3): SO2(g) + H2O(l) H2SO3(aq) Sulfur dioxide (SO2) can be oxidised gradually to sulfur trioxide (SO3): 2SO2(g) + O2(g) ‐‐‐‐‐> 2SO3(g) Sulfur trioxide (SO3) reacts with water to form sulfuric acid (H2SO4): SO3(g) + H2O(l) ‐‐‐‐‐> H2SO4(aq) • Oxides of nitrogen, particularly nitrogen dioxide (NO2) react with water to form nitrous acid (HNO2) and nitric acid (HNO3): 2NO2(g) + H2O(l) ‐‐‐‐‐> HNO2(aq) + HNO3(aq) 7
Combustion of Fuels
ACID RAIN Acid Carbonic acid (H2CO3)
Clean air Natural carbon dioxide (CO2) produced during plant and animal respirationproduced during decomposition of organic matter.
Polluted air Carbon dioxide (CO2) released from the combustion of fuels. The complete combustion of coal: C(s) + O2(g) ‐‐‐> CO2(g) The complete combustion of petrol, for example octane C8H18(l)): 2C8H18(l)+25O2(g)‐‐‐>16CO2(g)+18H2O(g) Complete combustion of ethanol (ethyl alcohol): C2H5OH(l)+3O2(g)‐‐‐>2CO2(g)+3H2O(g)
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Objectives • Study the chemical composition of the air and discuss the ideal of air quality in relation to the idea of human and environmental health. • Discuss the idea of air pollutant and study some of them.
Note: All, or most, of the objectives will be covered during class time, however the student must be responsible for those objectives not covered or concluded.
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Vocabulary • • • • •
Air Pollution Acid Rain Fumes Hazard
Note: Most of the vocabulary words will be covered during class time, however the student must be responsible for those words not covered or concluded.
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Link and Learn You can visit the following websites to improve your understanding on the present topic: • • • • • •
www.eea.europa.eu/ www.epa.gov www.breathingearth.net/ http://science‐learning2009.wikispaces.com http://learningandscience.blogspot.com http://libraryatstgeorge.blogspot.com
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Prepared by
Gerardo LAZARO Science Lead Teacher Email: glazaro@sanjorge.edu.pe Wiki: http://science‐learning2009.wikispaces.com Blog: http://learningandscience.blogspot.com Twitter: http://twitter.com/glazaro
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