7/26/10

Interesting things my teacher said

"a destroyer of worlds molecule"

Never has death looked so odd. Once used in refridgerators, the molecule above was used to preserve food "One of the most important molecules in the history of man." Its also inert and won't react with much. So why is that bad? Well it won't react until it floats to the top of the atmosphere - but then it gets hit by a photon - a radical reaction occurs - it'll then react with o3 until 10,000 have been broken down into 02, depleting our ozone molecules
(plethora of 03 molecules up above = the ozone layer)

Interesting things my teacher said

  • If you mix some propane with lots of dibromine.. u can just expose the bromine to light and that's enough energy for them to become radicals.. and then u can put the container someplace dark.. and slowly and slowly the bromine's will start a chain reaction until it's completely finished.. and they've attached to the propane (sorta like the CFC attacker in the pic)
  • CFC's .. a carbon/clorine/2 florines is a chemical used to refrigerate things and has 'saved many lives'.. "an extremely important molecule that saved the world".. but it's inert.. and won't react with anything until it gets to the top of the atmosphere.. then light will hit it.. it will break the carbon florine bond.. then it'll resonate and react with ozone and make o2... so 1 cfc molecule will bust 10,000 o^3 molecules (ozone).. and is the reason why the ozone layer gets depleted from 'bad refrigerants'
  • Reason people talk about 'rate limiting' steps in a reaction is because there's usually two steps.. and the first one requires energy and only a few will get to it in a bucket load.. and the molecule can go back to the starting materials or go forward.. the idea is it chooses forward because the step is so small (smaller than backward).. hence the idea that the whole reaction depends on this initial hump ('transition state')
  • It's not always the case 'the most stable' molecule is always formed.. some hammond guy observed this and put it in terms of 'how the molecule looks midway' (transition state) - basically noticing if a reaction gives off energy.. the transition stage (first one).. will look like the starting materials .. which is obvious because that means the biggest obstacle was the first hump.. and that's presumably the rate limitor.. if it's endo and requires energy.. it means there's a big ass hump.. takes longer to get to it.. and that transition state will look like the product (more obvious)
  • Bromine and propane is a weird one.. there are 6 hydrogens in propane that are at the ends (those carbons only stick to 1 other one.. the middle carbon sticks to 2 carbons and has only 2 hydrogens) - u would think odds are bromine would replace one of the hydrogens at the end (6 out of 8 hydrogens so 75% chance).. but instead it's 8% likely to take those.. and it's 92% likely to take the 2 out of 8 in the middle.. picky SOB... main idea is it takes less energy to attach a bromine to a 2ndary carbon.... (2ndary has lower activation energy)

This is a very superficial understanding of the above topics

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