posted by Liz .
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?
The pure element is zero. All elements in their standard state are zero.