A 0.12m^3 rigid tank contains saturated refrigerant R134a at 800kPa. Initially 25 percent of the volume is occupied by liquid and the rest by vapor. A valve at the bottom of the tank is now opened and liquid is withdrawn from the tank. Heat is transferred to the refridgerant such that the pressure in the tank remains constant. The valve is closed when no liquid is left in the tank and vapor starts to come out. Determine the total heat transfer for this process.