takes place isobarically and isothermally in a PFR where $63\mathrm{.}2\%$ conversion is

achieved. The feed is pure A$.$ It is proposed to put a CSTR of equal volume upstream

of the PFR$.$ Based on the entering molar flow rate to $A$ to the first reactor, what will

be the intermediate from the CSTR$,x_1,$ and exit conversion from the PFR$,x_2,$ based on the feed

to first reactor? The entering flow rates and all other variables remain the same as that for the

single PFR$.$ Source: Modified California Registration Exam Problem. $($Ans$.$: $x_2=0\mathrm{.}82)$