Liquid water at 200 kPa and 20 \deg C enters a chamber at 2.5 kg/s, where it is mixed with superheated steam at 200 kPa and 150 \deg C. The chamber loses 1200 kJ/min of heat to the surroundings, which are at 25 \deg C. If the mixture exits the chamber at 200 kPa and 60 \deg C, determine (a) the mass flow rate (kg/s) of the superheated steam, and (b) the rate of entropy generation (kW/K) in the mixing chamber.