A masslesss piston divides a closed thermallyy insulated cylinder into two equal parts. One part contains M = 28 g of nitrogen. At this temperature, one-third of molecules are dissociated into atoms and the other part is evacuated. The piston is released and the gas fills the whole volume of the cylinder at temperature `T_(0)`. Then, the piston is slowly displaced back to its initial position. calculate the increases in internal energy of the gas. Neglect further dissociation of molecules during, the motion of the piston.