Question $2$:

A stream of pure gaseous reactant liter$)$ enters a plug flow reactor at a flow rate of $F_{A,0}=540$mmo$\frac{l}{m}in$ and polymerizes there as follows.

$3AR$;$-r_A=54\frac{\text{m}\text{m}\text{o}\text{l}}{\text{l}\text{i}\text{t}\text{e}\text{r}*min}$

How large a reactor is needed to lower the concentration of $A$ in the exit stream to $C_{A,f}=330$mmo$\frac{l}{?}$ liter?

$($Show all steps of algorithm of isothermal reactor design$)$