Question

Use the Van der Waals Law Calculator to find the volume of an ideal gas, nitrogen, and oxygen. How close are the values? Do you feel that that treating air (which is 78% nitrogen and 21% oxygen) as an ideal gas is reasonable?

Answer 1

Genrally pressure of the gas is 1 atm.

T = 2989 K

no. of moles of N2 = (wt/mol.wt) = (78/14) = 5.57

R = 0.0821 lit*atm*mol^-1 K^-1

V = ?

As per the vanderwaals equation PV = nRT

    V = 5.57*0.0821*298/1 = 136.3 lt

For O2 also same conditions

no. of moles of O2 = (21/32) = 0.66

Applying the Vanderwaals equation

V = 0.66*0.0821*298/1

V = 16.15 lt.

Yes, Composition of air is always constant at normal conditions and no chemical reactions occur

so we can treat air as ideal gas