Explanation:
The given data is as follows.
Temperature of dry bulb of air = 
Dew point =
= (10 + 273) K = 283 K
At the dew point temperature, the first drop of water condenses out of air and then,
Partial pressure of water vapor
= vapor pressure of water at a given temperature 
Using Antoine's equation we get the following.


= 0.17079
= 1.18624 kPa
As total pressure
= atmospheric pressure = 760 mm Hg
= 101..325 kPa
The absolute humidity of inlet air = 

= 0.00735 kg
/ kg dry air
Hence, air leaving the humidifier has a has an absolute humidity (%) of 0.07 kg
/ kg dry air.
Therefore, amount of water evaporated for every 1 kg dry air entering the humidifier is as follows.
0.07 kg - 0.00735 kg
= 0.06265 kg
for every 1 kg dry air
Hence, calculate the amount of water evaporated for every 100 kg of dry air as follows.

= 6.265 kg
Thus, we can conclude that kg of water the must be evaporated into the air for every 100 kg of dry air entering the unit is 6.265 kg.