Physical Chemistry Real gases Critical data and equations of state Combination of ( 8.15)to(8.17) 36 mc (8.15 8a (8.16 27R6 a 27b2 (8.17) Predicts the compressibility factor at the critical point C mc 0.375 rt 8 (8.19) Van der waals equationCritical data and equations of state Combination of (8.15) to (8.17) 2 27b a Pc = (8.16) V b m c 3 , = (8.15) Rb a Tc 27 8 = (8.17) 0.375 8 , 3  = = c c m c c RT PV Z (8.19) Physical Chemistry Real Gases Predicts the compressibility factor at the critical point Van der waals equation