Physical Chemistry Real gases as virial equation of state d2=0 For a perfect gas =B+2PC+…→BaP→0 For a real gas There may be a temperature at which Z>1 Z with zero slope at low pressure. ( Boyle n) The properties of the real gas Higher do coincide with those of a perfect gas as P->0 Perfect gas Pressure ower Tvirial equation of state Z Pressure 1 Perfect gas Higher T Lower T For a perfect gas = B'+2PC'+ → B' as P → 0 dP dZ  = 0 dP dZ For a real gas There may be a temperature at which Z→1 with zero slope at low pressure. (Boyle T) The properties of the real gas do coincide with those of a perfect gas as P→0. Physical Chemistry Real Gases