A 0.831-g sample of SO3 is placed in a 1.00-L container and heated to 1100 K. The SO3 decomposes to SO2 and O2: 2SO3(g) <----> 2SO2(g) + O2(g). At equilibrium the total pressure in the container is 1.300 atm. Calculate Kp for the above reaction at 1100K.