Assume we have an adiabatic container that has an adiabatic partition within. In the left part of the container we have 1 mol Ar(g) under 100 kPa and 300 K; in the right part we have 2 mol N₂(g) under 200 kPa and 400 K. Now we take away the partition and let the gas spontaneously mix with each other until approaching the equilibrium. Calculate for the entropy change S of the mixing process.