One thousand kg h'' of a 35 wt% acetic acid-in-water solution is to be extracted with pure isopropyl ether supplied at a rate of 2,000 kg h'. (15 marks] (a) calculate and compare the percentage recovery of the acetic acid from the aqueous phase feed stream for the following arrangements: i) single-stage contact [2 marks) ii) cross-flow (successive) four (4)-stage contact with equal proportions of the ether solvent fed to each stage. [3 marks] (b) if the separation is to be carried out using a continuous counter-current extraction cascade, how many equilibrium stages will be required to achieve the same degree of acid recovery as that found in a (ii) above? (3 marks] (c) what minimum solvent rate would be required to yield the same raffinate composition as in (b)? (3 marks) (d) if an existing counter-current extraction column of six (6)-equilibrium stages is used, what would be the percentage recovery of acid achieved?