Class22

Class22 - Adverse Effects of Current Technologies on...

Info iconThis preview shows pages 1–11. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Adverse Effects of Current Technologies on Atmosphere International Concerns: I. Acid Rain II. Ozone Depletion III. Climate Change (Global Warming) Tro, page 327 [H + ] = 10-pH Increasingly Acidic Increasingly Basic pH = -log 10 [H + ] or [H + ] = 10-pH [H + ] http://www.uvprocess.com/product.asp?code=PH+++++++B I. Acid Rain: pH quantifies acidity pH of common substances (average) http://wpcontent.answers.com/wikipedia/commons/thumb/4/46/PH_scale.png/350px-PH_scale.png Pure water has a pH = 7 Natural rainwater has a pH 5.6 due to H 2 CO 3 Acid rain has a pH < 5.6 due to presence of additional acid(s): HNO 3 and/or H 2 SO 4 . Acid rain is defined as rain having a pH < 5.6 pH of rain depends on presence/absence of three oxides in air: CO 2 , NO 2 , and SO 3 These oxides react with rain water to produce acids: H 2 CO 3 , HNO 3 , and H 2 SO 4 ; respectively Natural rain contains only H 2 CO 3 and has an acidity of pH 5.6 Acid rain contains H 2 CO 3 plus HNO 3 and/or H 2 SO 4 and has a pH < 5.6 http://nadp.sws.uiuc.edu/isopleths/maps1999/phfield.gif All rain falling on US is acidic (pH < 7), but only rain having pH < 5.6 is defined as acid rain Record low pH http://portal.unesco.org/education/en/file_download.php/139c5df78bcee496e053ef6052c4a5e3How+acid+rain+is+formed+frame.jpg *Dry deposition - gas adsorbs onto surface of particulate matter. Forms acidic solutions when later contacted by water. Makes up about 50% of deposition. * Source of acid rain is combustion of fossil fuels CaCO 3 + H + Ca 2+ + HCO 3 - Limestone reacts with acids: Unprotected areas: Al 2 Si 2 O 5 (OH) 4 + 6 H + 2 Al 3+ + 2 SiO 2 + 5 H 2 O (Clay) (toxic) Adverse effects of acid rain on lithosphere and hydrosphere are decreased by limestone Buell/Girard, Chemistry, Prentice Hall, NJ, 1994, 232 Figure. Uncolored areas are protected by natural limestone deposits. Figure. Marble tombstone that has been exposed to acid rain in England since 1817. Raven et al, Environment, Saunders, NY, 1995, 450 Acid rain dissolves marble statues and monuments: CaCO 3 + H + Ca 2+ + HCO 3 - Adverse effect of acid rain on materials Schwartz et al, Chemistry in Context, ACS, DC, 1994, 171 Buell/Girard, Chemistry, Prentice Hall, NJ, 1994, 232 Acid rain releases toxic Al 3+ ions that kill trees and fish Clean Air Act amendments (1990) deal with acid rain by mandating reductions in its precursors: SO 2 and NO 2 ....
View Full Document

Page1 / 37

Class22 - Adverse Effects of Current Technologies on...

This preview shows document pages 1 - 11. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online