Q1. (50 pt) A feed solution containing 19% NaOH is evaporated until 38% NaOH content in a double-effect reverse feed evaporator. The feed stream of 1000 kg/h enters the second effect at 37.8 C. The pressure in the second effect is 12.35 kPa. The saturated steam used for heating is at 115 C. The temperature differences (AT) in each effect are assumed to be equal (AT =AT2). a) Calculate the steam economy (Cpsteam=1.884 kJ/kgC). b) The vapor leaving the evaporator goes to a barometric condenser (direct contact condenser). The temperature of the cooling water is 25C and the discharge water leaves the condenser at 45C. Calculate the cooling water flow to the condenser (Cpwater-4.18 kJ/kgC)