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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: Fastlane51 on October 09, 2008, 01:47:39 PM

Title: Which produces more CO2 per liter during combustion? Ethanol or Octane?
Post by: Fastlane51 on October 09, 2008, 01:47:39 PM

This is assuming the desity of Octane is .699g/mL and Ethanol is .785g/mL.
I have already done this I just want to check my answer

molecular weight of Octane: 114.2g
                           Ethanol: 46.07g

And what is the mass produced per liter?

Thanks for any help

Title: Re: Which produces more CO2 per liter during combustion? Ethanol or Octane?
Post by: Borek on October 09, 2008, 02:03:08 PM

Well, one gives 1500 g, second 2154 g. Compare to your results and you will know if they are OK.

Title: Re: Which produces more CO2 per liter during combustion? Ethanol or Octane?
Post by: Fastlane51 on October 09, 2008, 02:22:27 PM

Oh well I got 1499.86g for CH3CH2OH
and 2154.57g for C8H18

HAHA I promise I am not trying to use this to get homework down, its just that I saw a website that claimed that 1 liter of octane produces more heat than 1 liter of ethanol, so it got me doubting the rest of my calculations.
I think the website must be wrong because everything I did was right

I got that ethanol produced -6.028KJ/g
and octane produces -2.189KJ/g
as well

sooo i am sure that website is wrong....

Title: Re: Which produces more CO2 per liter during combustion? Ethanol or Octane?
Post by: Borek on October 09, 2008, 03:24:10 PM

My bet - without checking any numbers - is that octane gives more energy both per mass and per volume.