Question

For oxygen gas, the van der Waals equation of state achieves its best fit for a=0.14 N⋅m^4/mol^2 and b=3.2×10^(−5) m^3/mol

1.Determine the pressure in 2.0 mol of the gas at 10 ∘C if its volume is 0.24 L , calculated using the van der Waals equation.

2. Determine the pressure in 2.0 mol of the gas at 10 ∘C if its volume is 0.24 L , calculated using the ideal gas law.

Answer 1

since , in the case of real gases, intermolecular forces are present between the molecules. this intermolecular force reduces the volume of real gas by an amount = nb .

the finite size of molecules in real gas increases the pressure of gas. the constant  'a' provides this correction to pressure.and 'b' provides correction to volume.so we use van der Waals equation .(given in notes)

in ideal gas , there is no intermolecular forces and we assume their molecules are point particles.there for we use PV=nRT equation