A bimolecular (elementary) second-order reaction, takes place in a homogeneous liquid system. Reactants and products are mutually soluble, and the volume change as a result of reaction is negligible. Feed to a tubular (plug-flow) reactor that operates essentially isothermally at 260°F consists of 210 lb/h of A and 260 lb/h of B. Total volume of the reactor is 5.33 ft ³ , and with this feed rate, 50% of compound A in the feed is converted. It is proposed that to increase conversion, a stirred reactor of 100-gal capacity be installed in series with, and immediately upstream of, the tubular reactor. If the stirred reactor operates at the same temperature, estimate the conversion of A that can be expected in the revised system; neglect the reverse reaction. Other available data include:

(Ans.: X = 0.68.) (California Professional Engineers Exam)
[2nd Ed. P4-11]