Two kg of N2 at 450 K, 7 bar is contained in a rigid tank connected by a valve to another rigid tank holding 1 kg of O2 at 300 K, 3 bar. The valve is opened and gases are allowed to mix, achieving an equilibrium state at 370 K. Determine a) the volume of each tank, in m3 . b) the final pressure, in bar. c) the heat transfer to or from the gases during the process, in kJ. d) the entropy change of each gas, in kJ/K