JEE Advanced levelOne or more correct optionsDifficulty 3 of 3rg132
A van der Waals gas has a=1.39L2atmmol−2 and b=0.0391Lmol−1. Two moles are placed in a 1.00L vessel at 300K (R=0.0821LatmK−1mol−1). Which statements are correct?
AThe free volume is 0.9218L
BThe pressure correction term is 5.56atm
CThe van der Waals pressure is about 47.9atm
DThe gas exerts a lower pressure than an ideal gas would
Answer: A, B, C, D
V−nb=1.00−2×0.0391=0.9218L (A true). an2/V2=1.39×4/1.00=5.56atm (B true). P=0.92182×24.63−5.56=53.44−5.56=47.88atm (C true). Ideal: P=49.26atm, so the real pressure is lower (D true).