Energey Density of Carbon Monoxide

[Kasper_NYC]

Hi,

Please, does someone know the “energy density” of Carbon Monoxide – CO? I would like to know how much energy gives the combustion of Carbon Monoxide with Oxygen.

Also it would be great (if it is possible) to know approximately the temperature of the flame when burning in oxygen.

I have looked for it several days in the Net and I couldn't find anything.

Thanks a lot.

 

[Ygggdrasil]

You should be able to calculate it by looking up the heat of formations of CO and CO₂ then applying Hess's law (look it up in a general chemistry text or on wikipedia http://en.wikipedia.org/wiki/Hess's_law). This should give you the amount of heat released during the combustion of CO, but I don't think it will help you find the temperature of the flame as that will depend on many factors and is not easily calculated.

 

[russ_watters]

Here are the energies - I think you can just subtract the two from each other: http://chemistry.about.com/library/weekly/blheatform.htm

 

[Kasper_NYC]

Hi, Ygggdrasil.

Thank you! I have look at it as you explained to me. From this web:

http://test.sdsu.edu/testhome/Test/solve/basics/tables/tablesComb/formation.html

I found the “heat of formation of CO”: and I guess it is: -110.5 Kj/mol. (I am not sure because shows two different values, but I am pretty sure should be this one.) So from the Hess’s law that you suggested:

Heat of formation of Oxygen (O2): 0 Kj/mol
Heat of formation of Carbon Monoxide (CO): -110.5 Kj/mol
Heat of formation of Carbon Dioxide (CO2): -393.5 Kj/mol

2CO + O2 = 2CO2

AH = AHcP – AHcR

AH = [2 * -393.5)] - [(2 * -110.5) + (0)] = -566 Kj/mol

I think this is the right answer, please could you confirm it?

Thanks a lot.

 

[Kasper_NYC]

Thank you Russ! You posted while I was writing my answer with my Word processor (I got to check my English the all time), and I didn’t realize your post with the link.

Thanks both of you.

 

[Ygggdrasil]

Yes, your answer is correct, but remember that your original equation is 2CO + O₂ --> 2CO₂. Therefore, for every two moles of CO₂ formed, 566kJ are released. This means that for every mole of CO₂ formed, 283kJ are released.

H_f on the table represents the heat of formation (also known as enthalpy of formation) and is used to calculate the heat released by the reaction. G_f is the free energy of formation and takes into account the entropy change of the reaction. It is used more for calculating equilibrium constants.