In general, real gases behave most ideally at temperatures and pressures. the behavior of real gases can be described using the van der waals equation [p + (n2a/v2)](v-nb) = nrt the values of a and b are given below for the two real gases krypton and xenon. the gas in which deviations from ideal behavior due to intermolecular forces are expected to be the largest is . the gas that would be expected to behave least like an ideal gas at high pressures is . gas a (l2atm/mol2) b (l/mol) kr 2.32 3.98×10-2 xe 4.19 5.11×10-2