How do I calculate the molar volume and pressure correction terms in the van der Waals equation of state for "CO"_2 if the density of "CO"_2 at a certain temperature is "4.4 g/L", while a = "3.6 L"^2cdot"atm/mol"^2 and b = "0.04 L/mol"?

1 Answer
Dec 7, 2017

The van der Waals (vdW) volume correction and pressure correction terms in

P = (RT)/(barV - b) - a/(barV^2)

are:

barV_"corr" = barV - b

P_"corr" = a/(barV^2)

where barV = V/n is the molar volume, a is the vdW term for intermolecular forces, and b is the vdW term for excluded volume of a non-point-mass particle.

Therefore:

barV_"corr" = "1 L"/(4.4 cancel"g" cdot "1 mol"/(44.01 cancel("g CO"_2))) - "0.04 L"/"mol"

= ul"9.96 L/mol"

P_"corr" = (3.6 cancel("L"^2)cdot"atm"/cancel("mol"^2))/([1 cancel"L"//4.4 cancel"g" cdot cancel"1 mol"/(44.01 cancel("g CO"_2))]^2)

= ul"0.360 atm"