The new enthalpies, which are 181kJ (66.4kJ + 114.6kJ).
The objective of this classic Hess' Law problem is to have all unnecessary reactants or products cancel out when runs 1 and 2 are added.
When the second rxn is flipped, we obtain N2(g)+2O2(g)—>2NO2(g)?
H°1 = + 66.4 kJ
2NO2(g) -> 2NO(g) + O2(g)
H°2=+114.2kJ
Notice how the enthalpy flips signs as well as we flipped the rxn.
The rxns are now simply added to obtain...
N2(g) + 2O(g) = 2NO2(g)?
H°1 = + 66.4 kJ 2NO2(g) -> 2NO(g) + O2(g)?
H°2=+114.2kJ
N2(g) + O2(g) --> 2NO(g) is all that is left, and this is what we desire.
The new enthalpies are now included, giving a total of 181kJ (66.4kJ + 114.6kJ).
Learn more about Enthalpies here-
https://brainly.com/question/13996238
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