Problem 2.151

A thermally insulated vessel is partitioned into two parts so that the volume of one part is $n=2.0$ times greater than that of the other. The smaller part contains $v_{1}=0.30$ mole of nitrogen, and the greater one $v_{2}=0.70$ mole of oxygen. The temperature of the gases is the same. A hole is punctured in the partition and the gases are mixed. Find the corresponding increment of the system's entropy, assuming the gases to be ideal.