A non$-$elementary reaction is given by

A $+2$B $=$Product$($s$)$

The reactor is fed at a flow rate of $500$ L$/$min$.$ The feed contains $0\mathrm{.}2$ kmol A$/$L and $0\mathrm{.}3$ kmol B$/$L$.$ The exit stream contains $0\mathrm{.}05$ kmol B$/$L$.$ The rate of reaction is given by $$rA$=$ kA CA CB$.$ By considering reactant B as limiting reactant, design a CSTR necessary to achieve the required conversion of B$.$ Take kA $=0\mathrm{.}002$ L$/($kmol$$s$).$ Hint: Start with GMBE in terms of reactant B