A 1-m3 tank containing air at 25 °C and 500 kPa is connected through a valve to another tank containing 5 kg of air at 35 °C and 200 kPa. The valve is now opened and the entire system is allowed to reach thermal equilibrium with the surroundings, which are at 20 °C. Determine the volume of the second tank and the final equilibrium pressure of the air.