An insulated rigid tank is divided into two compartments by a partition. One compartment contains 8 kg of oxygen gas at 42oC and 100 kPa, and the other compartment contains 4 kg of nitrogen gas at 20oC and 180 kPa. The partition is then removed and the two gases are allowed to mix. Determine
(a) The mixture temperature
(b) The mixture pressure after equilibrium has been reached.