1 / 32

Announcements

Announcements. Today’s lecture is brought to you by the number…. 10 Electron Transfer Reactions* Oxidation & reduction (revisited). Geez….almost all reactions are this!. Hindenburg: oxidation of hydrogen by oxygen, reduction of oxygen by hydrogen.

muncel
Download Presentation

Announcements

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Announcements

  2. Today’s lecture is brought to you by the number… 10 Electron Transfer Reactions* Oxidation & reduction (revisited) Geez….almost all reactions are this!

  3. Hindenburg: oxidation of hydrogen by oxygen, reduction of oxygen by hydrogen. http://www.youtube.com/watch?v=CgWHbpMVQ1U http://www.youtube.com/watch?v=xiAT9xvTVKI&feature=related 2H2 4H+ + 4e- Oxidation Half Rxn 4e- + O2 2O2- Reduction Half Rxn _____________________ 2H2 + O2  4H+ + 2O2-  2H2O

  4. RedOx means Reduction and Oxidation; They go hand-in-hand. RedOx means Reduction and Oxidation; They go hand-in-hand.

  5. This is the “smoke on the water” reaction we saw on video. 2Na + 2H2O 2Na+ + H2 + 2OH- Na was oxidized: Na  Na+ + e- (electron lost) H was reduced: lost oxygen O no change: lost H but gained e- Remember…we can actually run this reaction by dumping some sodium into water.

  6. ReDox in organic systems is tricky. 2 CH3OH  2 CH2O + H2 C: ??? H: ??? H: ??? O: ???

  7. CH3CH2CH2CH=CHCH2CH3 + H2 CH3CH2CH2CH-CHCH2CH3 H H This one is very tricky (and related to “butter vs. margarine”) C ????? H ?????

  8. Not-so-Secret Agents: all part of the semantics nightmare that is RedOx • Something that promotes reduction: reducing agent • Example: K, Na, H, LiAlH4 • Something that promotes oxidation: oxidizing agent • Example, O, F, Br, K2Cr2O7

  9. Main Applications of RedOx Recovery of metals from ores Corrosion Prevention of corrosion Batteries

  10. Steel! And the sons ofPullman porters & the sons of engineersRide their fathers' magic carpet made of steel Mothers with their babes asleep, rockin' to the gentle beatAnd the rhythm of the rails is all they feel City of New Orleans—Steve Goodman

  11. A country that makes stuff makes steel.

  12. Reducing Iron Ore to Make Steel:from rust to riches 2 Fe2O3 + 3C 4 Fe + 3CO2 From Coal Rust i.e., ore How steel is really made: http://www.sidmar.be/CONTENT/2c.htm

  13. RedOx contributes to our geography, history and economics. IRON ORE CARS COAL Why a steel factory in Louisiana?

  14. Electro-reduction for aluminum production takes much energy. 2Al2O3 4Al + 3O2 http://www.terragalleria.com/images/us-ca/usca10035.jpeg http://www.ocrwm.doe.gov/youth/images/powerplant.jpg Electrons supplied Electronsreturned Power Plant http://www.epa.gov/highgwp/aluminum-pfc/images/exhibit3.gif

  15. Aluminum production affects/has affected geography, too. Hydroelectric Power Aircraft Industry Hydroelectric Power

  16. Why do we recycle aluminum? http://www.recycle.novelis.com/Recycle/EN/Kids/Fun+Facts/Many+Lives+of+the+Aluminum+Can/

  17. Corrosion is the auto restorer’s enemy! 2 Fe  2 Fe+2 + 4 e- 4e- + 2H2O + O2  4OH- Electrons travel down nail http://cardesign.homestead.com/BaraMtn72.jpg Rust on my Barracuda  Someday, someday…

  18. Batteries! What if we could trap those electrons, make ‘em do some work before the reduction step?

  19. ENR vs XOM

  20. Fuel Cells—a quick intro to why we need chemistry and chemical engineers. Honda FCX fuel cell concept at ~100 mph on a test track. It goes 354 miles without refueling with hydrogen. How soon? Soon! http://www.youtube.com/watch?v=y3VtrzcKQk Hey…where are we gonna get the hydrogen? Images from treehugger.com (no kidding, that’s the site!)

  21. We are reliant on foreign oil. http://www.worldfuturefund.org/wffmaster/Charts-HTML/Energy/us-oil.htm But maybe not forever, thanks (?) to fracking to recover natural gas. U.S. oil imports as a percentage of consumption

  22. http://www.saudi-us-relations.org/newsletter/saudi-relations-12.htmlhttp://ils.unc.edu/~lanck/images/Roosevelt.jpghttp://www.saudi-us-relations.org/newsletter/saudi-relations-12.htmlhttp://ils.unc.edu/~lanck/images/Roosevelt.jpg

  23. Let’s go to the fabulous HowStuffWorks site to see how Fuel Cells work. Clickable: http://auto.howstuffworks.com/fuel-cell3.htm Pasteable: http://auto.howstuffworks.com/fuel-cell3.htm So, what are the technical challenges? The hydrogen has to come from somewhere. Transport of the protons across the polymer membrane requires the membrane be hydrated and liquid. The membrane (think of it as a sulfonated teflon) is expensive and can be damaged or fouled. The electrodes can become fouled. Expensive metals are used to catalyze the reaction.

  24. About one billion dollars has been spent so far. Is that a lot? Approx 5% of the budget of one of America’s poorest states (LA). Twelve hundred times less than estimated project costs of a certain military intervention in the Mideast. (N.Y. Times estimate $1200 Billion) Ford and Airstream Concept Fuel Cell Minivan

  25. Don’t believe everything you see! http://www.allthingsbeautiful.com/all_things_beautiful/images/churchill_roosevelt_stalin.jpg

  26. I still haven’t said where the H2 comes from. Look at this Los Angeles Solar Parking lot, though.

  27. At the other end of I-10 is a windfarm.

  28. Hybrid Vehicles: operate on gasoline with a battery storage system.RedOx Chemistry Galore “The car Detroit wants you to believe cannot be built.” But is that fair???

  29. Hybrid Locomotive: GM is great at this stuff.

  30. Chevy Volt is now selling….slowly.

  31. Cool Fuel Cell Links How Stuff Works Link: http://science.howstuffworks.com/fuel-cell1.htm http://science.howstuffworks.com/framed.htm?parent=fuel-cell.htm&url=http://education.lanl.gov/resources/h2/gottesfeld/education.html

  32. “Maybe I should invest in fuel cells.”P. Russo, 1999

More Related