1. Predict the mass transfer coefficient for liquid ammonia vaporising into air at 1 atm, 25°C, knowing that the heat transfer coefficient in the same equipment, at the same gas and liquid flow rates,...

1. Predict the mass transfer coefficient for liquid ammonia vaporising into air at 1 atm, 25°C, knowing that the heat transfer coefficient in the same equipment, at the same gas and liquid flow rates, is 4.544 kW/m²
K.

2. Atmospheric air at 30°C flows over a wet-bulb thermometer which reads 20°C. Calculate the concentration of water vapour in the air stream and the relative humidity of the air.