Extraction

a$)$ Using a multistage counter$-$current extraction, product $C$ shall be separated from the diluent A$.$ Please use the ternary diagram provided on the supplementary sheet to solve this task. The feed consists of $62\%$ C and $38\%$ A$.$

b$)$ The added solvent flow $S^{\text{'}}$ is saturated with A but free of $C.$ Please mark the feed $F,$ the solvent $S^{\text{'}}$ and the notional mixing point $M$ of the total process. The ratio of solvent stream to feed $(\frac{S^{\text{'}}}{F})$ is $\frac{3}{2}.$

c$)$ The outlet raffinate composition of the last separator step $R_n$ may not contain more than $4\%$ of $C.$ Please construct the pole point $.$ What is the content of $C$ in the extract stream $E_1?$