It is proposed to reduce the concentration acetaldehyde in aqueous solution from 55% to 5% by mass, by extraction with solvent S at 293K. If a counter current multiple contactor process is adopted and 0.025 kg/s of solution are treated with an equal quantity of solvent, determine
(b) the number of theoretical stages required
(c) the concentration of the extract
(d) the mass of the extract from the first stage.
The equilibrium relationship at 293 K