Consider the reaction $AB,r=k.C_A,k_{300}=0\mathrm{.}05mi{n}^{-1},H_R=-20$kca$\frac{l}{m}$ole in a $10$ liter peactor with $C_{A0}=2$ moles$/$liter and $T_0=300K.$ at what rate must heat be removed to maintain the reactor isothermai at $300K$ and $90\%$ conversion for PFR$?$