An air–water vapor mixture enters a heater–humidifier unit at 5° C, 100 kPa, and 50% relative humidity. The flow rate of dry air is 0.1 kg/s. Liquid water at 10° C is sprayed into the mixture at the rate of 0.0022 kg/s. The mixture leaves the unit at 30° C and 100 kPa. Calculate

(a) The relative humidity at the outlet.

(b) The rate of heat transfer to the unit.