Matronics Email Lists :: View topic - Carbon Bon Bons (Brians post)

Matronics Email Lists
Web Forum Interface to the Matronics Email Lists

Get Email Distribution Too! FAQ Search Memberlist Usergroups Register

Profile Log in to check your private messages Log in

Carbon Bon Bons (Brians post)

Matronics Email Lists Forum Index -> Yak-List

View previous topic :: View next topic

Author Message

lacloudchaser(at)yahoo.co
Guest

Posted: Wed Nov 14, 2007 8:34 am Post subject: Carbon Bon Bons (Brians post)

Brian, 

  

 After speaking to several class rooms of high school kids on a career as an Air Force officer and pilot with a part time volunteer staff position, and seeing the total "deer in the head light" look at the mention of  further education, college or developing a curiosity for learning/education, it's impressive you bother to attack such subjects, apparently out of the shear enjoyment of making the unknown - known, 

  

 "BTW, I encourage someone to show me where I am wrong as I always am  

looking to learn."



 Brain, perhaps there is a chemical engineer/BBS or Forum you could also cut and paste your arguments to as well? It may provide the extra (and focused) feedback and analysis that is suitable to your quest?

  

 Drew

  

 Time: 09:11:48 AM PST US

From: Brian Lloyd <brian-1927(at)lloyd.com (brian-1927(at)lloyd.com)>

Subject: carbon bonds (was: mogas vs 100LL)

I hate it when something sticks in my head overnight. It means I am  

not going to get a good night's sleep. (Yes, I do lose sleep over  

stuff like this. Yes, I probably am crazy.)



The issue was the comment about higher grades of fuel having more  

carbon-carbon bonds and therefore more energy. The Wikipedia article  

I referenced, http://en.wikipedia.org/wiki/Octane_rating, also  

alluded to that. OTOH I figured that if there was an appreciable  

increase in C-C bonds there would be a shift in best stoichiometric   

mixture when measured by mass ratio.



As a mental experiment I decided to trot out my old and rotten  

chemistry memories to compare the two simplest organic compounds with  

single and double carbon-carbon (c-c) bonds: ethane (C2H6) and ethene  

(C2H4). Ethane has a single C-C bond and ethene has a double C=C  

bond. Combusting ethene should release more energy than combusting an  

equivalent mass of ethane. Here is what the two molecules look like:



Ethane:



  H H

  | |

H-C-C-H

  | |

  H H



Ethene:



H    H

  \  /

  C=C

  /  \

H    H

When you have the double carbon bond you no longer have bonds for the  

two extra hydrogens. This changes the combustion reaction from:



2(C2H6) + 7(O2) = 4(CO2) + 6(H2O) + energy



To:



C2H4 + 3(O2) = 2(CO2) + H2O +  energy



The mass of ethane is 30gm/Mol. The mass of ethene is 28gm/Mol. The  

mass of O2 is 32gm/Mol. So the oxidizer-to-fuel mass ratios for the  

two reactions are:



7(32)/2(30) = 3.73 (for ethane)



3(32)/28 = 3.42 (for ethene)



This is a 9% difference in mass ratio. (I didn't include the N2 from  

the atmosphere because, while it does change the individual mass  

ratios, it does not effect the percentage difference at the end which  

is what I was looking for.)



My gut feeling is, if "higher quality" gasoline had a lot more C=C  

(double) bonds (and therefore more energy), we would have to readjust  

our carburetors when we switch fuel in order to get a proper mixture.  

Since we don't ...



BTW, I encourage someone to show me where I am wrong as I always am  

looking to learn.



--

Brian Lloyd                         3191 Western Drive

brian HYPHEN 1927 AT lloyd DOT com    Cameron Park, CA 95682

+1.916.367.2131 (voice)            +1.270.912.0788 (fax)



I fly because it releases my mind from the tyranny of petty things . . .

Antoine de Saint-Exupry



PGP key ID:          12095C52A32A1B6C

PGP key fingerprint: 3B1D BA11 4913 3254 B6E0  CC09 1209 5C52 A32A 1B6C

________________________________  Message 2   _____________________________________

       Get easy, one-click access to your favorites.    [quote][b]

- The Matronics Yak-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Yak-List

brian-1927(at)lloyd.com
Guest

Posted: Wed Nov 14, 2007 10:55 am Post subject: Carbon Bon Bons (Brians post)

On Nov 14, 2007, at 8:30 AM, Drew wrote:



 	  Quote: 	
		  



 Brian,



 After speaking to several class rooms of high school kids on a  

 career as an Air Force officer and pilot with a part time volunteer  

 staff position, and seeing the total "deer in the head light" look  

 at the mention of  further education, college or developing a  

 curiosity for learning/education, it's impressive you bother to  

 attack such subjects, apparently out of the shear enjoyment of  

 making the unknown - known,


	


Thank you Drew. I am now teaching science to 4th-8th grade students  

at a private school. I have them designing and building catapults,  

robots, radios, and even fuel cells. The "deer-in-the-headlights"  

problem you allude to may be laid firmly at the feet of our abortion  

of an education system. By getting the kids early enough and showing  

them that it is FUN to make and understand even complex things, I  

hope to offset the damage that the public school system is going to  

do to them later.



Just the other day I had a 5th grade girl ask me a question that  

indicated that she sees and understands the questions that lead from  

Michael Faraday's empirical work in electricity and magnetism, to  

James Clerk Maxwell's theoretical work on electromagnetic waves, work  

that led to the creation of radio. It tickles me no end when I see  

the light bulb go on like that.



When you stop "dumbing down" this stuff, they just eat it up,  

especially when they get to DO something with it. It is a kick to see  

kids this age writing software, soldering, putting up antennas,  

tracking satellites, reading weather charts, etc. Several even know  

how to use an E6B now. (I use it as a tool to demonstrate ratios and  

proportions.)



 	  Quote: 	
		  

 "BTW, I encourage someone to show me where I am wrong as I always am

 looking to learn."

 Brain, perhaps there is a chemical engineer/BBS or Forum you could  

 also cut and paste your arguments to as well? It may provide the  

 extra (and focused) feedback and analysis that is suitable to your  

 quest?


	


Perhaps I will, in my copious free time.  The school is currently  

eating about 60 hours/week of my time.



--

Brian Lloyd                         3191 Western Drive

brian HYPHEN 1927 AT lloyd DOT com    Cameron Park, CA 95682

+1.916.367.2131 (voice)             +1.270.912.0788 (fax)



I fly because it releases my mind from the tyranny of petty things . . .

— Antoine de Saint-Exupéry



PGP key ID:          12095C52A32A1B6C

PGP key fingerprint: 3B1D BA11 4913 3254 B6E0  CC09 1209 5C52 A32A 1B6C

- The Matronics Yak-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Yak-List

Display posts from previous:

	Matronics Email Lists Forum Index -> Yak-List	All times are GMT - 8 Hours
Page 1 of 1

Jump to:

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum