124. Solving a chemistry problem

222. 1 mol of NO2 gas was placed in a reaction vessel and heated until the equilibrium NO2(g)↔NO(g) 1/2O2(g) was established at a total pressure of 1 atm. At temperatures of 700 and 800 K, equilibrium ratios of mole fractions xNO/xNO2 were found to be 0.872 and 2.50, respectively. Calculate the equilibrium constants and Gibbs energies at these temperatures. Calculate the enthalpy of the reaction.