A gaseous feed in a PFR reactor is pure A $(2$ mol$/$L initial concentration, $100$ L$/$min

initial volume flowrate$).$ The reactor operates at constant temperature. B is produced

according to the reaction:

$2$A$=$B$+$C with a rate: $-$rA $=0\mathrm{.}5$ C A mol$/$L min

$-$Find the size of the reactor needed to convert $66\mathrm{.}7\%$ of A into B and C$.$