Liquid water at 200 kPa and 20 C is heated in a chamber by mixing it with superheated steam at 200 kPa and 150 C. Liquid water enters the mixing chamber at a rate of 1.3 kg/s, and the chamber is estimated to lose heat to the surrounding air at 25 C at a rate of 1140 kJ/min. If the mixture leaves the mixing chamber at 200 kPa and 60 C, determine (a) the mass flow rate of the superheated steam and (b) the rate of entropy generation during this mixing process.