A distillation column, at 1 atm, with a total condenser and a partial re-boiler is used to separate an ethanol (E1OH)-water mixture. The feed is20 mol% EtOH with a feed rate of 1,000 kmol/h (h = 25 Btu/lb)A distillate composition of 80 mol% EtOH and a bottom composition of2 mol% EtOH are required. The external reflux ratio is 5/3, and thereflux is a saturated liquid. If the CMO is assumed, find the number of.equilibrium stages and the optimal feed stage? Given the enthalpies for a saturated vapour (H) and a saturated liquid (h)of 880 and 125 Btu/lb, respectively. The problem statement can be described as the following flow chart:

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