Calculate dH for each reaction of interest (or all of them) as
dHrxn = (n*dHf products) - (n*dHf reactants) then compare to answer the question. Yes it is a state function because the sum is equal to the individual parts and to be a state function it doesn't matter how we get there. It only matters about the initial and final states.
Nitrogen and oxygen can react directly with one anotheer to produce nitrogen dioxide according to
N2(g) + 2O2(g) --> 2NO2(g)
The reaction may also be imagined to take place by first producing nitrogen oxide
N2(g) + O2(g) --> 2NO(g)
which then produces NO2
2NO(g) + O2(g) --> 2NO2(g)
The overall reaction is found by summing reactions and gives
N2(g) + 2O2(g) --> 2N2O(g)
How does the enthalpy change for the first reaction compare to that for the fourth reaction? Does this illustrate that enthalpy is a state function? Explain.
2 answers
Calculate the enthaplychange for the following reaction.
NO(g)+1/2O2(g) =NO2(g)
NO(g)+1/2O2(g) =NO2(g)