Question

• The humidity ratio of atmospheric air at 28 deg C DBT and 760 mm of mercury is 0.016 kg of
vapour per kg of dry air. What is partial pressure of water vapour in kN / m2​

Answer 1

Answer:

vapour density.

Solution: Given: td= 28°C ; Pb= 760 mm of Hg ; W = 0.016 kg/ kg of dry air 1. Partial pressure of water vapour

Let Pv= Partial pressure of water vapour.

We know that humidity ratio (W), 12.16 - 0.016 Pv= 0.622 Pv or 0.638 Pv= 12.16 Pv= 12.16/0.638 = 19.06 mm of Hg = 19.06 x 133.3 = 2540.6 N/m2Ans