Humidity
`relative\ humi d ity = (p artial\ pressure\ of\ H_2O)/(saturated\ vapo r\ pressure\ of\ H_2O) times 100%`
Example:
On a particular hot day, the temperature is `30°C` and the partial pressure of water vapor in the air is `21.0\ t o r r` What is the relative humidity?
Solution:
Water at 30°C the saturated vapor pressure is `31.8\ t o rr`
relative humidity `= (21.0\ t o rr)/(31.8\ t o rr) times 100% = 66%`