Show that another way of writing the flux due to pressure diffusion is in terms of partial molar volume and the total mixture density is

\[J_{\mathrm{A}}^{*}(\text { pressure diffusion })=-C D_{\mathrm{AB}} \frac{1}{R_{\mathrm{G}} T}\left(\tilde{V}_{\mathrm{A}}-\tilde{V}\right) abla P\]