Given that the feed to column $C3$ in the distillation operation in the figure and table below is to produce a distillate that is $95$mol$\%$ pure in iC $4$ with a recovery in the distillate yielding a split fraction $($SF$)$ of $96\%.$ There exists a relatively sharp separation in column $C_3$ between $i{C}_4$ and $n{C}_4,$ and it is assumed that all the propane gooes to the distillate, while all the C$5$s goes to the bottoms.