For the reaction:

Question

2 NO(g) + 1 O2(g) <--> 2 NO2(g)

Calculate K, the equilibrium constant, from thermodynamic data at 281 K.

(Hint #1: Assume that S and H do not change with temperature.)
(Hint #2: Work in J/mol)

Answer 1

I would determine DGo from
DGo rxn = (n*DGo products) - (n*DGo reactants)
Then since DG = 0 at equilibrium,
DGo = -RT*lnK