diffusion relative to volume average velocity

please do A and B. thanks!

1-2. Difinsion Relative to Volume-Average Velocity A reference frame sometimes chosen for diffusion is the volume-average velocity v(v). For a binary mixture this velocity is given by (v(v)=NAVA+NBVB, where VA and VB are the partial molar volumes of species A and B, respectively. The total molar concentration is related to the partial molar volumes and mole fractions by C=(xAVA+xBVB)1. The molar flux of A relative to the volume-average velocity. JA(v), is defined as JA(v)=NACAv(v) (a) Show that JA(v)VA+JB(v)VB=0 (b) Show that JA(v)=CVBJA(M)