Calculate the van der waals correction terms to pressure and volume for Cl2 at STP. The values of the van der waals constants a and b are 6.49L^2-atm/mol^2 and 0.0562 L/mol, respectively, for Cl2. At STP, which is the major cause of deviation from ideal behavior, the volume of the Cl2 molecules or the attractive forces between them? WHY?