Liquid reactants with an initial concentration of $100$ mol$/$L and a flow rate of $200$ L$/$min are flowed into the flow reactor. Answer the following questions when the reaction rate formula is $-$rA $=$ kCA$2$ and k $=50$ L$/$min$$mol$.$

$1)$ Find the reactor volume of MFR to obtain $80\%$ conversion of A$.$

$2)$ Find the conversion rate of A if you use the same volume of PFR as the MFR of $1).$