A liquid feed to a CSTR consists of $2000mo\frac{l}{m^3}$A and $2400mo\frac{l}{m^3}B.$ A second$-$order irreversible reaction takes place as $A+B--2C$

The rate of reaction is given by $-r_A=k{C}_A^2$ where the reaction rate constant at $65C$ is $k=.$min$).$ Assume the reactor operates isothermally at $65C.$

a$)$ Calculate the residence time in mins required to obtain $80\%$ conversion of species A$.$

b$)$ What should be the volume of the reactor in $m^3$ if species $C$ are to be produced at a rate of $820mo\frac{l}{m}in?$