An insolated cylinder of volume V is divided in two equal chambers by separating wall. In each of them there is 1 mole of perfect monoatomic gas at different initial temperature, say T1 and T2. We need to calculate the change of anthropology in the following case. 1) the wall is thermally conductive. 2) the wall has a very small hole which allows the gas who pass to the other side. 3) the dividing wall breaks.