I am to use this formula to find ΔH°f,methane:

ΔH°comb=2ΔH°f,water+ΔH°f, carbon dioxide-ΔH°f,methane-2ΔH°f,oxygen

For ΔH°comb, the value is 884 KJ/mol
For ΔH°f,water, the value is -285.8
For ΔH°f,carbon dioxide, the value is -393.5

I was not given ΔH°f,oxygen, what value would it be?

Question

I am to use this formula to find ΔH°f,methane: 

ΔH°comb=2ΔH°f,water+ΔH°f, carbon dioxide-ΔH°f,methane-2ΔH°f,oxygen 

For ΔH°comb, the value is 884 KJ/mol 
For ΔH°f,water, the value is -285.8 
For ΔH°f,carbon dioxide, the value is -393.5 

I was not given ΔH°f,oxygen, what value would it be?

joannablackwelder · Answer

The standard heat of formation of all elements is 0. http://www.chemteam.info/Thermochem/StandardEnthalpyFormation.html

anonymous · Answer

Oh, so the answers is just ΔH°comb=0?

joannablackwelder · Answer

I don't think the combine is 0. You can find the standard heat of formation of methane in a table. Are you sure that is what you are solving for?

joannablackwelder · Answer

Oh, I just noticed that you were given the combined in your problem statement.

anonymous · Answer

Yes I'm sure that I am supposed to solve for ΔH°f,methane. I just don't know what to substitute ΔH°f,oxygen  for

joannablackwelder · Answer

The standard heat of formation of all elements is 0.

anonymous · Answer

Ok thanks!

joannablackwelder · Answer

No worries. :)