Table 2.1. Volume and molecular mass of air
The density of air can be computed using the ideal gas law, at a given pressure and temperature, as
...................................................................................(2.1)
where ua is the air pressure, wa the molecular mass, R the ideal gas constant, and T the temperature.
The density of the air can be calculated using the air pressure (assumed to be atmospheric) as 101.325 kPa, temperature is 298 K, the universal gas constant is 8.314 /mol-K, and assuming the molecular mass of air to be 28.97 kg/kmol
The air density is highly sensitive to the state variables viz. pressure and temperature. These atmospheric variables become the driving forces for the air transport from the location of higher density to the lower density. The sensitivity of these variables can be studied using the Eq. (2.2) as given by
........................................................................(2.2)