van der Waals Inflection Point Xi'an Universif dp RT 0 dvm (Wm-b)2 d"p 2RT 64 dva(V-b) =0 solution:Vm.e =3b and pe=a/27b2Xi’an University of Science & Technology van der Waals Inflection Point 2 3 2 2 3 4 2 , 2 0 ( ) 2 6 0 ( ) solution: 3 and / 27 m m m m m m m c c dp RT a dV V b V d p RT a dV V b V V b p a b = − + = − = − = − = =