A pyridine-water solution, \(50 \mathrm{wt} \%\) pyridine, is to be continuously and countercurrently extracted at the rate of \(2.25 \mathrm{~kg} / \mathrm{s}\) with pure chlorobenzene to reduce the pyridine concentration to \(2 \mathrm{wt} \%\).

(a) Determine the minimum solvent rate required.

(b) If \(2.3 \mathrm{~kg} / \mathrm{s}\) of solvent is used, calculate the number of theoretical stages required, and the flow rates of final extract and raffinate.