The gas constant for dry air rais 287 m2/s2 . k (here k stands for degrees kelvin) assuming the temperature is 280 k and the pressure is 130 kpa, what is the atmospheric density?

Atmospheric density,

Given:

Gas constant for dry air, R = 287

Temperature of gas,

Pressure of gas,

Solution:

Now, to calculate the atmospheric density, we follow:

The eqn for an ideal gas is given by:

where

n = no. of moles of gas

n =

Also, we can write,

Comparing both the values of n, we get:

        (1)

Now, the molecular mass of air can be calculated as:

(Since, Oxygen and nitrogen constitutes to about 21% and 78% in the atmosphere)

Using the value above in eqn (1):