7.4-3. Minimum Solvent and Countercurrent Extraction of Acetone. An aqueous feed solution of 1000kg/h containing 23.5wt% acetone and 76.5 wt \% water is being extracted in a countercurrent multistage extraction system using pure methylisobutyl ketone solvent at 298-299 K. The outlet water raffinate will contain 2.5wt \% acetone. Use equilibrium data from Appendix A.3. a. Calculate the minimum solvent that can be used. [Hint: In this case, the tie line through the feed L0 represents the condition for minimum solvent flow rate. This gives V1min. Then, draw lines LNV1min and L0VN+1 to give the mixture point Mmin and the coordinate xAMmin. Using Eq. (27.4-4), solve for VN+1min, the minimum value of the solvent flow rate VN+1.] b. Using a solvent flow rate of 1.5 times the minimum, calculate the number of theoretical stages