Separate 1,2-dichloroethane from 1,1,2-trichloroethane at 1 atm. Distillate is \(99.15 \mathrm{~mol} \%\) 1,2-dichloroethane, and bottoms is 1.773 \(\mathrm{mol} \%\) 1,2-dichloroethane. Saturated liquid feed is \(60.0 \mathrm{~mol} \% 1,2-\) dichloroethane. Relative volatility is approximately constant, \(\alpha=2.4\).

a. Find the minimum number of stages using the Fenske equation.

b. Calculate \(\mathrm{L} / \mathrm{D}_{\text {min }}\).

c. Estimate the actual number of stages for \(\mathrm{L} / \mathrm{D}=2.2286\) using the Gilliland correlation.

d. A detailed simulation gave \(99.15 \mathrm{~mol} \% 1,2\)-dichloroethane in the distillate, \(1.773 \mathrm{~mol} \% 1,2\)-dichloroethane in the bottoms for \(\mathrm{L} / \mathrm{D}=\) \(2.2286, \mathrm{~N}=25\) equilibrium contacts, and optimum feed location is 16 equilibrium contacts from the top of the column. Compare this \(\mathrm{N}\) with part \(\mathrm{c}\), and calculate the percent error in the Gilliland prediction.