A 1-m3 tank containing air at 25C and 500 kPa is connected through a valve to another

Question:

A 1-m3 tank containing air at 25◦C and 500 kPa is connected through a valve to another tank containing 4 kg of air at 60◦C and 200 kPa (Fig. P3.232). Now the valve is opened and the entire system reaches thermal equilibrium with the surroundings at 20◦C. Assume constant specific heat at 25◦C and determine the final pressure and the heat transfer.